Pediatric heat stroke: The danger of children left in hot cars

JC Gonzalez, DO
University of Florida – Gainesville

As of June 2024, the United States is experiencing a significant heat wave, with temperatures reaching record highs across many states. This extreme weather condition increases the risk of pediatric heat stroke, making it imperative for emergency medicine physicians to be vigilant and prepared. Heat stroke is a critical and potentially fatal condition that demands immediate attention and intervention. In pediatric cases, one of the most alarming and preventable causes of heat stroke is the entrapment of children in overheated vehicles.

Pathophysiology

Heat stroke occurs when the body’s thermoregulatory mechanisms are overwhelmed, leading to an increase in core body temperature. In young children, heat stroke risk is heightened due to several factors including reduced thermoregulatory capacity, inefficient sweating mechanism, and a greater surface area-to-body mass ratio.

The principal mechanism of heat loss in a hot environment is evaporation. However, this becomes ineffective above a relative humidity of 75%.¹ The other major methods of heat dissipation cannot efficiently transfer heat when the environmental temperature exceeds skin temperature.

Even on mild days, the temperature inside a parked car can rapidly escalate, often reaching life-threatening levels within minutes. This risk is exacerbated during a heat wave. For example, even in an ambient temperature of 75°F, a car can exceed 100°F in just 30 minutes. In summer, with a temperature of 90°F, a car’s internal temperature will be over 100°F in just 5 minutes.²

Clinical Presentation

The manifestations of pediatric heat stroke can be severe and progress rapidly. Key signs and symptoms are as follows:

• Hyperthermia: Core body temperature exceeding 104°F (40°C)
• Neurological Impairment: Altered mental status, seizures, delirium, and coma.
• Skin Changes: Hot, dry skin is typical, although sweating may still be present in some cases.
• Cardiovascular Instability: Tachycardia, hypotension, and potential cardiovascular collapse
• Respiratory Distress: Hyperventilation or respiratory failure can occur in severe cases.

Management

Prompt recognition and aggressive management of heat stroke in children are paramount.

• Immediate Cooling
  • Children with heat stroke require aggressive treatment because the extent of end-organ damage and mortality is related to the duration of hyperthermia.³ Initiate rapid cooling by removing the child from the hot environment, undressing them, and applying cool water to the skin. Evaporative cooling with fans can be effective. In the pre-hospital environment, the use of ice or cold-water immersion can be beneficial in rapidly lowering the core body temperature.
  • When at the hospital, the use of a cooling blanket, application of ice packs to the neck, axilla, and groin as well as the use of room-temperature normal saline may complement evaporative cooling efforts. However, the use of cooling blankets or ice packs is associated with shivering, which may require suppression with benzodiazepines.
• Monitoring and Support: Continuous monitoring of vital signs, core temperature, and neurological status. Be prepared to manage seizures and provide advanced airway support if necessary.
• Transfer: Expediate transfer to a facility capable of providing intensive care, including potential renal support for rhabdomyolysis and multi-organ dysfunction management.

Prevention and Advocacy

Emergency physicians play a crucial role not only in the acute management of heat stroke, but also in prevention through advocacy and education. Key prevention strategies include:

• Parental Education: Educate parents and caregivers about the dangers of leaving children in cares, even for short periods.
• Public Awareness Campaigns: Support and disseminate information on the importance of “Look Before You Lock” initiatives.
• Legislative Measures: Advocate for laws and regulations mandating safety features in vehicles. One such example is recent federal legislation that requires all new vehicles by the 2025 model year must carry a rear passenger alert system. Read more about this legislation. 

Conclusion

Heat stroke in children left in hot cars is a preventable tragedy that requires vigilance and proactive measures. In the context of the current heat wave, the need for awareness and preventative action is even more pressing. Emergency physicians must be adept at recognizing the signs of pediatric heat stroke and implementing rapid, effective treatment protocols.

References

1. Bross MH, Nash BT Jr, Carlton FB Jr. Heat emergencies. Am Fam Physician. 1994 Aug;50(2):389-96, 398.
2. Walker Dando. Vehicle heat safety for children. https://ufhealth.org/stories/2023/vehicle-heat-safety-for-children. Accessed July 26, 2024.
3. Kanda J, Nakahara S, Nakamura S, et al. Association between active cooling and lower mortality among patients with heat stroke and heat exhaustion. PLOS One. 2021 Nov 17;16(11):e0259441. doi: 10.1371/journal.pone.0259441.