Plain-English guide for Kentucky parents about therapeutic hypothermia after hypoxic-ischemic encephalopathy.
Updated August 2026
When a newborn shows signs of hypoxic-ischemic encephalopathy (HIE) after birth, one treatment can make a meaningful difference for babies who meet the medical criteria:
therapeutic hypothermia, commonly called cooling therapy.
The timing matters.
For newborns at least 36 weeks’ gestation with moderate-to-severe HIE, the best-established treatment is to lower the baby’s core temperature to approximately 33.5°C and begin treatment within six hours after birth, continue cooling for 72 hours, and then gradually rewarm the baby.
That six-hour window is not arbitrary.
It comes from the major randomized clinical trials that established therapeutic hypothermia as an effective treatment for HIE.
But the current guidance is also more nuanced than simply saying:
“After six hours, it is too late.”
The American Academy of Pediatrics’ 2026 clinical report states that cooling started between 6 and 24 hours may be considered in otherwise eligible newborns after discussion with the family about the possibility of a small benefit and the associated risks.
The priority, however, remains clear:
Recognize HIE early and start therapeutic hypothermia as soon as possible when the baby qualifies.
What Is Hypoxic-Ischemic Encephalopathy?
Hypoxic-ischemic encephalopathy, or HIE, describes brain dysfunction associated with inadequate oxygen and blood flow around the time of birth.
“HIE” should not be assumed solely because:
- A baby’s Apgar score was low
- A C-section was performed
- Cord blood was acidic
- The baby required resuscitation
- The baby was admitted to the NICU
- The baby received cooling therapy
Doctors generally consider multiple pieces of evidence.
These can include:
- Pregnancy and labor events
- Fetal-heart-rate patterns
- Placental abruption, cord prolapse, uterine rupture, or another acute event
- Umbilical cord blood gases
- Early newborn blood gases
- Duration of resuscitation
- Apgar scores
- Neurologic examination
- Seizures
- EEG findings
- MRI findings
- Other possible causes of newborn encephalopathy
The AAP’s 2026 report specifically cautions that clinicians should consider a broad differential diagnosis, even when HIE is suspected.
Cooling a baby does not, by itself, prove what caused the baby’s encephalopathy.
What Is Therapeutic Hypothermia?
Therapeutic hypothermia deliberately reduces a newborn’s body temperature under highly controlled conditions.
For the population in whom treatment has been best established, the standard regimen is approximately:
Target temperature: 33.5°C, generally within a 33.5–34.5°C range
Cooling duration: 72 hours
Start: ideally within the first 6 hours after birth
Rewarming: gradual, commonly about 0.5°C per hour
The baby is closely monitored throughout treatment.
This is very different from a baby simply becoming cold accidentally.
Therapeutic hypothermia is a specialized intensive-care treatment requiring precise temperature control and monitoring.
Why Does Cooling Help?
Brain injury following a hypoxic-ischemic event does not necessarily occur all at once.
After the initial oxygen and blood-flow disruption, a cascade of secondary cellular injury can continue over the following hours.
Therapeutic hypothermia is intended to slow that process and reduce additional brain injury during a period when some cells may still be salvageable.
Cooling can affect processes involving:
- Cellular metabolism
- Inflammation
- Excitotoxicity
- Oxidative injury
- Programmed cell death
- Other mechanisms involved in secondary brain injury
The treatment cannot undo every injury that has already occurred.
It is a neuroprotective treatment, not a guarantee of normal neurological development.
Why Is the Six-Hour Window So Important?
The landmark clinical trials that established therapeutic hypothermia enrolled eligible newborns and initiated treatment within six hours after birth.
Across the major studies:
- Cooling began within approximately six hours
- Target temperatures were around 33.5–34.5°C
- Treatment generally continued for 72 hours
- Newborns had moderate-to-severe encephalopathy and evidence supporting a hypoxic-ischemic event
Those studies showed that therapeutic hypothermia reduced the combined risk of death or major neurodevelopmental disability compared with usual care in appropriately selected newborns.
The AAP’s 2026 clinical report therefore continues to describe cooling initiated within six hours as the established standard.
The 2025 AHA/AAP neonatal resuscitation guidelines likewise recommend therapeutic hypothermia under defined protocols for newborns 36 weeks or greater with moderate-to-severe HIE.
Does Cooling Have to Start Exactly Before Hour Six?
The first six hours remain the best-supported treatment window.
But current guidance does not treat 6:00 hours as though a biological switch suddenly turns off.
That distinction is important.
The AAP recommends:
Initiate cooling as soon as possible.
The goal should not be:
“We have six hours, so there is no rush.”
A baby who clearly meets treatment criteria at two hours of age ordinarily should not have cooling intentionally delayed until five hours and 59 minutes.
Earlier identification gives clinicians more opportunity to provide treatment during the period in which its benefit has been most clearly established.
What If HIE Is Recognized After Six Hours?
This is one of the areas where medical guidance has changed.
Older summaries often stated that cooling after six hours had not been demonstrated to help and therefore should not be used.
The AAP’s 2026 clinical report is more nuanced.
A randomized trial examined newborns at least 36 weeks’ gestation with moderate-to-severe HIE whose cooling was initiated between 6 and 24 hours after birth.
The trial did not establish the same degree of benefit seen with early cooling. However, its Bayesian analysis suggested the possibility of a small treatment benefit.
Based on that evidence, the AAP now states that cooling between 6 and 24 hours may be considered when:
- The baby otherwise has moderate-to-severe HIE
- Cooling was not started within the first six hours
- The potential benefits and risks are discussed with the parent or guardian
- The reasoning and discussion are documented
This does not make delayed cooling equivalent to cooling begun in the first six hours.
Early identification and treatment remain the priority.
What If the Baby Was Initially Mild and Worsened Later?
Newborn neurological examinations can evolve.
A baby who initially appears relatively well may develop:
- Increasing lethargy
- Abnormal tone
- Weak suck
- Abnormal reflexes
- Seizures
- Other evidence of encephalopathy
That is one reason serial examinations can matter during the first hours after birth when HIE is suspected.
If a baby does not initially meet cooling criteria but later develops moderate-to-severe encephalopathy within the relevant treatment period, the neonatal team may reassess eligibility.
When a baby presents between 6 and 24 hours, the AAP’s 2026 guidance allows consideration of delayed cooling after discussing the more limited evidence with the family.
Which Babies Usually Qualify for Cooling?
Eligibility protocols differ somewhat among hospitals because the original clinical trials used slightly different criteria.
However, the best-established treatment population generally includes several components.
1. Gestational Age
36 Weeks or Greater
The strongest evidence supports therapeutic hypothermia for babies born at:
36 0/7 weeks’ gestation or later
with moderate-to-severe HIE.
Both the AAP 2026 report and the 2025 AHA/AAP neonatal resuscitation guideline support cooling for this population under appropriate protocols.
What About Babies Born at 35 Weeks?
This is an important update.
The AAP’s 2026 clinical report says evidence regarding cooling babies born at:
35 0/7 through 35 6/7 weeks
is limited.
Cooling may be considered on a case-by-case basis after discussing potential risks and benefits with the family.
The reason for caution is important.
A randomized clinical trial involving infants born at 33–35 weeks found no reduction in death or moderate/severe disability with therapeutic hypothermia.
The Bayesian analysis found:
- A 74% probability that cooling increased death or disability
- An 87% probability that cooling increased death
However, the trial was not large enough to separately establish whether the findings were the same for the relatively small subgroup of babies born specifically at 35 weeks.
For that reason, the AAP does not recommend routine cooling for all 35-week infants, but permits individualized consideration.
What About Babies Younger Than 35 Weeks?
The AAP’s current recommendation is clearer:
Therapeutic hypothermia is not recommended for babies born before 35 weeks’ gestation.
The randomized trial of infants born at 33–35 weeks did not show benefit and raised concern for possible harm.
The 2025 AHA/AAP neonatal resuscitation guideline similarly states that cooling infants younger than 36 weeks has not demonstrated benefit and may be associated with harm.
This is one area where gestational age materially changes the evidence.
2. Evidence Supporting a Perinatal Hypoxic-Ischemic Event
Cooling is not based solely on a neurological examination.
Protocols generally also look for evidence that hypoxia-ischemia occurred around birth.
Depending on the protocol, that evidence can include:
- Significant metabolic acidosis on cord blood gas
- Significant acidosis on a blood gas obtained soon after birth
- Low Apgar score at 10 minutes
- Continued need for assisted ventilation at 10 minutes
- Prolonged neonatal resuscitation
- An acute perinatal event plus additional qualifying findings
Examples of acute events can include:
- Umbilical-cord prolapse
- Placental abruption
- Uterine rupture
- Significant fetal-heart-rate deterioration
- Maternal hemorrhage
- Maternal cardiac arrest
- Other events capable of interrupting fetal oxygenation
What Cord-Gas Numbers Are Used?
Different trials used somewhat different criteria.
For example, the NICHD whole-body cooling trial used:
pH ≤7.00
or:
Base deficit ≥16 mmol/L
on an umbilical cord or other blood sample obtained during the first 60 minutes after birth.
The trial also had a pathway for babies with less severe gas abnormalities—or no available gas—when additional clinical criteria were present.
Those numbers are useful for understanding the history of cooling protocols.
They should not be treated as though one pH number independently diagnoses HIE or determines eligibility at every hospital.
The complete protocol matters.
3. Moderate or Severe Encephalopathy
Evidence of acidosis or a difficult delivery alone is not enough.
The baby generally must also demonstrate moderate-to-severe encephalopathy on neurological examination.
Clinicians may assess areas such as:
- Level of consciousness
- Spontaneous activity
- Posture
- Muscle tone
- Primitive reflexes
- Suck
- Moro reflex
- Autonomic function
- Respiratory pattern
- Seizures
A widely used approach is the modified Sarnat examination.
The original NICHD trial required moderate or severe findings in at least three of six examination categories.
Hospital protocols can vary.
What About Seizures?
Seizures can be an important sign of neonatal encephalopathy.
They can also be difficult to recognize.
Some neonatal seizures have obvious physical manifestations.
Others are detectable only on EEG.
The AAP’s 2026 clinical report notes that as many as half of newborns with moderate-to-severe HIE can experience seizures during the first 72 hours.
That is one reason continuous neuromonitoring is an important part of care during cooling.
Does a Baby Need an Abnormal EEG to Qualify?
Not necessarily.
The original cooling trials used different protocols.
Some required abnormal amplitude-integrated EEG findings.
Others—including the NICHD whole-body cooling trial—used clinical and biochemical eligibility criteria without making an abnormal EEG mandatory.
A hospital should follow its established protocol.
EEG is nevertheless extremely important after HIE has been identified because seizures may be electrographic without visible clinical signs.
Does Mild HIE Qualify for Cooling?
Current AAP guidance says:
Therapeutic hypothermia for mild HIE is not presently recommended outside a research study.
This is another area where treatment practices have sometimes expanded beyond the populations included in the original trials.
Mild HIE should not be dismissed as harmless. Research shows that some babies with mild HIE later experience developmental abnormalities.
But that does not establish that cooling improves their outcomes.
The AAP’s 2026 report concludes that evidence demonstrating the safety and effectiveness of cooling mild HIE remains insufficient.
Clinical trials are continuing.
What Happens Once Cooling Starts?
Cooling is only one part of HIE treatment.
A newborn receiving therapeutic hypothermia requires intensive monitoring and supportive care.
Continuous Temperature Monitoring
Therapeutic hypothermia requires precise temperature control.
The goal is not to make the baby “as cold as possible.”
The established target is approximately 33.5°C, generally maintained within a narrow target range.
Uncontrolled overcooling can create additional risks.
Continuous EEG Monitoring
The AAP recommends continuous neuromonitoring for newborns undergoing cooling.
Continuous video EEG is preferred when available.
Amplitude-integrated EEG may be useful when full continuous EEG is unavailable.
Monitoring is particularly important because newborn seizures may have no obvious outward movement.
Current guidance generally supports EEG monitoring through the cooling and rewarming period, although monitoring may sometimes be shortened in selected circumstances when early EEG is entirely reassuring.
Blood Pressure and Cardiovascular Monitoring
Cooling alters normal physiology.
The NICU monitors:
- Heart rate
- Blood pressure
- Circulation
- Cardiac rhythm
- Oxygenation
- Other cardiovascular measures
A slower heart rate can be an expected physiologic response to therapeutic hypothermia.
Blood Testing
Monitoring can include:
- Blood gases
- Glucose
- Electrolytes
- Kidney function
- Liver function
- Blood counts
- Platelets
- Coagulation studies
- Other testing depending on the baby’s condition
The goal is to maintain stable physiology while minimizing secondary brain injury.
Seizure Treatment
When seizures are confirmed, the neonatal and neurology teams determine whether anti-seizure medication is necessary.
EEG helps clinicians determine:
- Whether apparent events are actually seizures
- How frequently seizures occur
- Whether medication stops the electrographic seizures
- Whether seizures recur during cooling or rewarming
Brain MRI
The AAP’s 2026 report recommends MRI before hospital discharge for newborns who have undergone therapeutic hypothermia.
MRI after rewarming—commonly around days four or five or during the first week—can help identify the pattern and extent of brain injury.
MRI can also help evaluate diagnoses other than HIE.
A normal or abnormal MRI should still be interpreted together with:
- Neurological examination
- EEG
- Clinical course
- Laboratory findings
- Long-term development
Why Cooling Lasts 72 Hours
The standard 72-hour treatment period was established in the major clinical trials.
Researchers later tested whether making babies colder or cooling them longer would provide additional protection.
It did not.
A NICHD trial compared:
- 33.5°C for 72 hours
- 32.0°C for 72 hours
- 33.5°C for 120 hours
- 32.0°C for 120 hours
The trial was stopped early because of increased in-hospital mortality and concerns about futility.
There were more in-hospital deaths among infants assigned to the deeper and longer cooling strategies.
The evidence therefore continues to support the standard approach:
approximately 33.5°C for 72 hours
rather than “more cooling must be better.”
How Is the Baby Rewarmed?
After approximately 72 hours, the baby is gradually rewarmed.
The original trials generally used slow rewarming of approximately:
0.5°C per hour
Rapid, uncontrolled rewarming is avoided.
EEG and other monitoring may continue during this period because seizures and physiologic changes can occur during rewarming.
What Are the Risks of Therapeutic Hypothermia?
Cooling is generally considered safe in the population for whom its benefit has been established, but it is not risk-free.
Potential effects and complications include:
- Sinus bradycardia
- QT-interval prolongation
- Low platelet count
- Blood-pressure changes
- Coagulation abnormalities
- Electrolyte disturbances
- Skin changes or subcutaneous fat necrosis
- Other complications related to the baby’s underlying critical illness
The AAP notes that many adverse effects were uncommon in the major clinical trials.
Cooling therefore needs to occur under an established protocol with close NICU monitoring.
Is Cooling Proof That the Baby Suffered an Oxygen-Deprivation Injury?
No.
This distinction matters medically and legally.
A neonatologist may initiate cooling because the baby meets or appears to meet treatment criteria and because delaying treatment while every possible diagnosis is excluded could cause the treatment window to close.
That does not mean the eventual diagnosis must be HIE caused by intrapartum oxygen deprivation.
Newborn encephalopathy can have other causes, including:
- Stroke
- Intracranial hemorrhage
- Infection
- Metabolic disease
- Genetic disease
- Congenital abnormalities
- Medication effects
- Other neurologic disorders
The AAP specifically recommends maintaining a broad differential diagnosis.
A decision to cool is evidence about what clinicians were concerned about at the time.
It is not, by itself, proof of causation or malpractice.
Why Recognition Before Six Hours Matters
The six-hour treatment window creates a practical problem for delivery hospitals:
There may not be much time to recognize HIE, determine eligibility, call a tertiary center, arrange transport, and initiate cooling.
For a baby with significant risk factors, the early timeline matters.
Important events may include:
- Birth
- Apgar assessments
- Cord-gas result
- Resuscitation
- First postnatal blood gas
- First abnormal neurological examination
- Seizure activity
- Neonatology consultation
- Cooling-center consultation
- Decision to cool
- Cooling started
- Transport requested
- Transport team activated
- Departure
- Arrival at the receiving NICU
Minutes can matter because all of these events are occurring during the first several hours of life.
Does a Baby Have to Reach the NICU Before Cooling Can Begin?
Not necessarily.
The AAP’s 2026 clinical report specifically addresses cooling during transport.
When an eligible newborn cannot reach a tertiary cooling center within the first six hours, cooling before and during transport may be considered under an established protocol.
The report says servo-controlled cooling is preferred over passive cooling when possible because it provides better temperature control and reduces the risk of overcooling.
That means the question is not always:
“When did the baby arrive at the children’s hospital?”
It may also be:
“When was therapeutic hypothermia actually initiated?”
What Is Passive Cooling?
Passive cooling generally means reducing external warming—for example, turning off a radiant warmer—rather than immediately using a servo-controlled cooling blanket.
The AAP’s 2026 algorithm notes that passive cooling may be initiated when HIE criteria are met or there is high suspicion while further treatment is being arranged.
But passive cooling is not something parents should attempt themselves.
It requires:
- Medical supervision
- Core-temperature monitoring
- Vital-sign monitoring
- An established protocol
- Communication with the receiving neonatal team
Earlier experience demonstrated that uncontrolled passive cooling can result in overcooling.
Therapeutic hypothermia should be managed by trained medical personnel.
Kentucky Newborn Transport and the Six-Hour Window
Not every Kentucky delivery hospital has the resources to provide complete HIE cooling care.
A baby born at a community hospital may need transfer to a higher-level NICU.
Two transport programs Kentucky families may encounter are:
UK HealthCare — Kentucky Kids Crew
Kentucky Kids Crew provides hospital-to-hospital critical-care transportation for newborn and pediatric patients.
The team is directed by neonatologists and pediatric intensivists, operates 24/7, and provides ground and air transport to Golisano Children’s at UK.
For an HIE case, relevant records can include:
- Time the tertiary center was contacted
- Time transport was requested
- Team activation
- Team arrival
- Temperature before and during transport
- Cooling instructions
- Treatments during transport
- Departure
- Arrival
- Bedside handoff
Norton Children’s — “Just for Kids” Transport Team
Norton Children’s “Just for Kids” Transport Team provides 24/7 neonatal and pediatric interfacility transport by ground and helicopter.
The team includes registered nurses, respiratory therapists, and emergency medical technicians and can provide critical-care interventions during transport.
Norton Children’s Hospital in downtown Louisville operates a Level IV NICU.
Again, the important HIE timeline may begin before the transport team arrives.
The sending hospital’s chart and transport record should be reviewed together.
What If Transfer Took Several Hours?
Transport time alone does not answer whether care was appropriate.
Kentucky contains rural areas where physical distance to a tertiary NICU can be substantial.
A meaningful review asks:
- When did the baby first show qualifying signs?
- When was HIE suspected?
- When were cord or newborn blood gases available?
- When was the neurological examination performed?
- When was a neonatologist consulted?
- When was transfer requested?
- Was a cooling protocol discussed?
- Could cooling appropriately begin before transport?
- When did cooling actually start?
- How was temperature monitored?
- Was the baby overcooled or undercooled?
- What treatment occurred during transport?
The AAP’s current guidance allowing controlled cooling during transport is particularly relevant when arrival at a cooling center before six hours is not feasible.
What Records Should Kentucky Parents Request?
If you are trying to understand whether HIE was recognized and treated promptly, collect records from every facility involved.
Labor-and-Delivery Records
Request:
- Complete fetal-monitoring tracing
- Nursing notes
- Physician notes
- Medication administration record
- Oxytocin history
- Operative records
- Anesthesia records
- Delivery note
- Placental pathology, if performed
These records help establish what happened before birth.
Cord-Gas Results
Request both:
- Umbilical arterial gas
- Umbilical venous gas
when available.
Look for:
- pH
- PCO2
- PO2
- Bicarbonate
- Base deficit/base excess
- Collection time
Do not interpret a cord gas in isolation.
Newborn Resuscitation Record
Look for:
- Heart rate
- Respiratory status
- Positive-pressure ventilation
- Intubation
- Chest compressions
- Epinephrine
- Oxygen
- Duration of resuscitation
- Time spontaneous circulation and breathing improved
The 2025 AHA/AAP neonatal resuscitation guideline recommends examining newborns at least 36 weeks’ gestation who required advanced resuscitation for evidence of HIE and possible therapeutic-hypothermia eligibility.
Apgar Scores
Collect Apgar scores at:
- 1 minute
- 5 minutes
- 10 minutes
- Later intervals if scoring continued
Apgar scores are useful clinical information.
They do not independently diagnose HIE or establish medical negligence.
Early Blood Gases and Laboratory Results
The AAP recommends obtaining cord gases for depressed newborns when possible.
If a cord gas is unavailable, an early blood gas—ideally within the first hour—can help evaluate possible eligibility.
Request:
- Arterial gases
- Venous gases
- Capillary gases
- Lactate
- Glucose
- Other early laboratory testing
Neurological Examinations
Ask for documentation showing:
- Level of consciousness
- Activity
- Tone
- Posture
- Suck
- Moro reflex
- Pupillary findings
- Respiratory pattern
- Seizures
- Sarnat examination or other HIE scoring
Timing matters.
A neurological examination at 30 minutes may differ from one performed at three hours.
Cooling Records
Request documentation of:
- Decision to cool
- Who was consulted
- Cooling start time
- Method used
- Initial temperature
- Target temperature
- Time target temperature was reached
- Continuous temperature measurements
- Cooling interruptions
- Duration
- Rewarming start time
- Rewarming rate
- Time normal temperature was restored
EEG Records
Ask for:
- EEG start date/time
- EEG stop date/time
- Continuous video EEG report
- aEEG documentation if used
- Seizure events
- Anti-seizure medication administration
If possible, retain the final EEG reports along with the underlying digital study if it is available for release.
MRI and Imaging
Request:
- Head-ultrasound reports
- MRI report
- MRI images
- Other neuroimaging
The AAP recommends MRI before discharge for newborns treated with therapeutic hypothermia.
Transport Records
If the baby was transferred, request records from the transport provider separately when necessary.
Look for:
- Referral call
- Acceptance
- Activation
- Dispatch
- Arrival at sending hospital
- Baby’s condition
- Core temperature
- Cooling orders
- Cooling equipment or method
- Departure
- Vital signs during transport
- Treatments
- Arrival
- Handoff
These records can help establish precisely when the tertiary team became involved.
A Cooling-Therapy Timeline Parents Can Build
Use the medical records to fill in as much of this timeline as possible.
Time of birth:
1-minute Apgar:
5-minute Apgar:
10-minute Apgar:
Cord arterial pH/base deficit:
Cord venous gas:
Resuscitation continued until:
First newborn blood gas:
First concern for encephalopathy/HIE:
First neurological examination:
Moderate/severe findings documented:
First seizure or suspected seizure:
Cooling center/neonatologist contacted:
Decision to cool:
Cooling started:
Baby’s age when cooling started:
Target temperature reached:
Transport requested:
Transport team activated:
Transport team arrived:
Departure:
Arrival at cooling center:
Continuous EEG started:
Cooling completed:
Rewarming began:
MRI:
If a time or fact cannot be determined from the information you have, write:
Unknown
rather than guessing.
Frequently Asked Questions
Does cooling have to start within six hours?
Starting within the first six hours remains the best-supported and preferred treatment window.
The AAP recommends beginning therapeutic hypothermia as soon as possible when an eligible newborn has moderate-to-severe HIE.
Is it automatically too late at six hours and one minute?
No.
Current AAP guidance permits consideration of cooling between 6 and 24 hours for otherwise eligible newborns after discussing the possibility of a small benefit and associated risks with the family.
The evidence for delayed cooling is much less certain than the evidence supporting treatment begun within six hours.
Does that mean hospitals can wait 12 or 20 hours before cooling?
No.
The possibility of delayed cooling does not change the priority of early recognition and prompt initiation.
The AAP specifically states that the findings on delayed cooling do not change the goal of beginning treatment as soon as possible after birth.
Does every baby with low cord pH qualify?
No.
A low cord pH can be one part of the eligibility criteria, but cooling generally also requires clinical evidence of moderate-to-severe encephalopathy.
Protocols vary.
Does every baby with HIE get cooled?
No.
Eligibility depends on factors including:
- Gestational age
- Age after birth
- Evidence supporting hypoxia-ischemia
- Severity of encephalopathy
- Other diagnoses or medical considerations
Current evidence most strongly supports cooling newborns at least 36 weeks’ gestation with moderate-to-severe HIE.
Does mild HIE qualify?
The AAP’s 2026 clinical report says therapeutic hypothermia for mild HIE is not currently recommended outside a research study.
Researchers continue to study whether selected babies with mild HIE benefit.
Can a 35-week baby be cooled?
Possibly, but this is not routine standard treatment supported by the same level of evidence as cooling a baby at least 36 weeks.
The AAP states that infants born at 35 0/7 to 35 6/7 weeks may be considered individually after discussing potential risks and benefits with the family.
Can a 34-week baby be cooled?
Current AAP guidance says therapeutic hypothermia is not recommended below 35 weeks’ gestation.
A randomized clinical trial of babies born at 33–35 weeks did not demonstrate benefit and raised concern about increased mortality.
What temperature should the baby be cooled to?
The established target is approximately:
33.5°C
with clinical trials generally maintaining temperatures between about 33.5°C and 34.5°C.
Cooling substantially deeper has not been shown to improve outcomes and may increase harm.
Why not cool for longer than 72 hours?
A trial examining longer and deeper cooling was stopped early because of increased in-hospital mortality and concerns about futility.
Current AAP guidance continues to support approximately 72 hours at 33.5°C.
Should cooling begin during transport?
It may.
The AAP says cooling before and during transport can be considered when an eligible baby cannot reach a cooling center within six hours.
Servo-controlled cooling is preferred when available because it better maintains the intended temperature and reduces overcooling.
This should only occur under an appropriate medical protocol.
Is turning off the warmer enough?
Passive cooling can sometimes be used temporarily under a medical protocol while definitive cooling is being arranged.
But uncontrolled passive cooling carries a risk of excessive hypothermia.
Parents should never attempt to cool a newborn themselves.
Does cooling guarantee a normal outcome?
No.
Therapeutic hypothermia improves the odds for appropriately selected newborns, but some babies still die or experience:
- Cerebral palsy
- Epilepsy
- Developmental disability
- Cognitive impairment
- Motor impairment
- Feeding difficulties
- Other neurological complications
That is why long-term developmental follow-up remains important.
Does needing cooling prove malpractice occurred during delivery?
No.
Cooling indicates that clinicians believed the newborn had—or was at significant risk for—moderate-to-severe HIE and might benefit from neuroprotective treatment.
It does not establish:
- When an injury occurred
- What caused it
- Whether it was preventable
- Whether a healthcare provider violated the standard of care
Those questions require separate medical and legal analysis.
What if cooling was started late?
A meaningful review asks why.
Important questions can include:
- When did the baby first meet eligibility criteria?
- When were abnormal cord or blood-gas results available?
- When did the neurological examination become abnormal?
- Were serial examinations performed?
- When was neonatology contacted?
- Did the hospital have an HIE screening protocol?
- When was the tertiary center called?
- Could cooling appropriately have begun before transfer?
- What did the transport team do?
- What was the baby’s temperature during the delay?
- Did the baby actually qualify earlier?
The fact that cooling began after six hours does not by itself establish negligence.
The underlying timeline matters.
Questions About Delayed HIE Cooling in Kentucky?
If your child was diagnosed with HIE and you have questions about whether therapeutic hypothermia was recognized and started promptly, the most useful starting point is usually the first six hours of the medical record.
Morrin Law Office can help identify records that may show:
- When oxygen-related concerns first arose
- Cord-gas and early blood-gas results
- Duration of resuscitation
- Neurological examination findings
- When HIE was suspected
- When a cooling center was contacted
- When cooling was ordered
- When cooling actually started
- Whether cooling occurred during transport
- When the baby arrived at the tertiary NICU
- EEG, MRI, and newborn findings
You do not need to know whether a six-hour “rule” was violated before asking questions.
The goal is to reconstruct what actually happened.
Call Morrin Law Office for a free consultation
859-358-0300
214 W Main St., Richmond, KY 40475
Sources and Public Resources
- American Academy of Pediatrics — Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy: Clinical Report (2026). This is the current AAP clinical report addressing standard cooling within six hours, treatment between 6 and 24 hours, late-preterm infants, mild HIE, cooling during transport, EEG monitoring, MRI, and long-term follow-up.
AAP — Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy - American Heart Association/American Academy of Pediatrics — 2025 Guidelines for Neonatal Resuscitation. Recommends therapeutic hypothermia under clearly defined protocols for newborns at least 36 weeks’ gestation with moderate-to-severe HIE and describes the 33.5–34.5°C, within-six-hours, 72-hour treatment framework.
AAP — 2025 AHA/AAP Neonatal Resuscitation Guidelines - Shankaran et al. — Whole-Body Hypothermia for Neonates with Hypoxic-Ischemic Encephalopathy, New England Journal of Medicine (2005). Landmark NICHD randomized trial establishing the benefit of whole-body therapeutic hypothermia initiated within six hours for eligible newborns with moderate-to-severe encephalopathy.
PubMed — Whole-Body Hypothermia for Neonates With HIE - TOBY Study Group — Moderate Hypothermia to Treat Perinatal Asphyxial Encephalopathy. Major randomized clinical trial evaluating whole-body cooling initiated within six hours and continued for 72 hours in newborns with perinatal asphyxial encephalopathy.
PubMed — TOBY Trial - Laptook et al. — Effect of Therapeutic Hypothermia Initiated After 6 Hours of Age on Death or Disability Among Newborns With Hypoxic-Ischemic Encephalopathy, JAMA (2017). Randomized trial examining therapeutic hypothermia initiated between 6 and 24 hours after birth. The findings form the basis for current AAP guidance allowing consideration of delayed cooling after discussion of possible small benefit and risk.
JAMA — Late Therapeutic Hypothermia Trial - Faix et al. — Whole-Body Hypothermia for Neonatal Encephalopathy in Preterm Infants 33 to 35 Weeks’ Gestation, JAMA Pediatrics (2025). Randomized trial finding no reduction in death or disability and Bayesian probabilities suggesting possible increased harm in infants born at 33–35 weeks.
JAMA Pediatrics — Cooling in Infants Born at 33–35 Weeks - Shankaran et al. — Effect of Depth and Duration of Cooling on Death or Disability at Age 18 Months Among Neonates With Hypoxic-Ischemic Encephalopathy, JAMA (2017). NICHD trial examining deeper and longer therapeutic hypothermia; results support the established approximately 33.5°C-for-72-hours protocol rather than deeper or prolonged cooling.
JAMA — Depth and Duration of Cooling Trial - American Academy of Pediatrics News — 2026 HIE Cooling Report Summary. Summarizes the updated AAP recommendations, including ≥36-week standard eligibility, individualized consideration at 35 weeks, possible treatment between 6 and 24 hours, and cooling during transport.
AAP News — Updated Therapeutic Hypothermia Recommendations - UK HealthCare — Kentucky Kids Crew. Provides 24/7 hospital-to-hospital neonatal and pediatric critical-care transportation by ground and air to Golisano Children’s at UK.
UK HealthCare — Kentucky Kids Crew Emergency Transport - Norton Children’s — “Just for Kids” Transport Team. Provides 24/7 specialized neonatal and pediatric interfacility transportation by ground and helicopter.
Norton Children’s — “Just for Kids” Transport Team - Norton Children’s — Neonatal Intensive Care Unit. Information on Norton Children’s Level IV NICU and regional neonatal services.
Norton Children’s — NICU Locations
Disclaimer
This page provides general educational information about HIE and therapeutic hypothermia. It is not medical advice and should not be used to decide whether a newborn currently needs cooling or another treatment.
Therapeutic hypothermia is specialized NICU care. If you have questions about a newborn who is currently hospitalized, ask the treating neonatologist or medical team immediately.
This page is also not individualized legal advice. An HIE diagnosis, abnormal cord gas, cooling decision, delayed cooling, transfer, seizure, MRI finding, or neurological outcome does not by itself establish medical negligence or causation.
The significance of cooling timing depends on gestational age, the baby’s condition, when qualifying findings appeared, applicable treatment protocols, transport circumstances, medical records, and other case-specific evidence.
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