Heat illness (other than heat stroke) in children
- Paul Ishimine, MD
Paul Ishimine, MD
- Clinical Professor of Emergency Medicine and Pediatrics
- University of California, San Diego School of Medicine
- Section Editor
- Daniel F Danzl, MD
Daniel F Danzl, MD
- Section Editor — Environmental Emergencies
- Professor of Emergency Medicine
- University of Louisville School of Medicine
- Deputy Editor
- James F Wiley, II, MD, MPH
James F Wiley, II, MD, MPH
- Senior Deputy Editor — Adult and Pediatric Emergency Medicine
- Senior Deputy Editor — Primary Care Sports Medicine (Adolescents and Adults)
- Professor of Pediatrics and Emergency Medicine/Traumatology
- University of Connecticut School of Medicine
The manifestations, evaluation, and management of heat illness in children other than heat stroke will be reviewed here. Heat stroke in the pediatric patient and heat illness in the adult patient are discussed separately. (See "Heat stroke in children" and "Severe nonexertional hyperthermia (classic heat stroke) in adults".)
Body temperature is maintained within a narrow range by balancing heat load with heat dissipation. The body's heat load results from both metabolic processes and absorption of heat from the environment. Evaporation is the principal mechanism of heat loss in a hot environment, but this becomes ineffective above a relative humidity of 75 percent. The other major methods of heat dissipation — radiation (emission of infrared electromagnetic energy), conduction (direct transfer of heat to an adjacent, cooler object), and convection (direct transfer of heat to convective air currents) — cannot efficiently transfer heat when environmental temperature exceeds skin temperature (typically 35ºC or 95ºF).
Children differ from adults with respect to their anatomical and physiologic response to heat stress. These differences translate into a potentially greater risk for severe heat illness in children, especially infants and young athletes [1,2]. The pathophysiology of heat illness in children is discussed in greater detail separately. (See "Heat stroke in children", section on 'Pathophysiology'.)
EVALUATION AND MANAGEMENT
All heat-related illnesses result from excessive heat exposure caused by an increased environmental heat burden, an inability of the body to dissipate endogenous heat, or a combination of these two factors. There are many manifestations of heat-related illnesses (table 1).
Miliaria (heat rash) — Miliaria is a common finding in newborns, especially in warm climates. It may also occur in older individuals. Accumulation of sweat beneath eccrine sweat ducts results in obstruction by keratin at the level of the stratum corneum. Pruritus is common. Several types of lesions may result (see "Benign skin and scalp lesions in the newborn and young infant", section on 'Miliaria'):
- Kerr ZY, Casa DJ, Marshall SW, Comstock RD. Epidemiology of exertional heat illness among U.S. high school athletes. Am J Prev Med 2013; 44:8.
- Xu Z, Etzel RA, Su H, et al. Impact of ambient temperature on children's health: a systematic review. Environ Res 2012; 117:120.
- Ishimine P. Hyperthermia. In: Pediatric Emergency Medicine, Baren JM, Rothrock SG, Brennan JA, Brown L. (Eds), Saunders Elsevier, Philadelphia 2008. p.992.
- Howe AS, Boden BP. Heat-related illness in athletes. Am J Sports Med 2007; 35:1384.
- DeFranco MJ, Baker CL 3rd, DaSilva JJ, et al. Environmental issues for team physicians. Am J Sports Med 2008; 36:2226.
- Lukins JL, Feldman MJ, Summers JA, Verbeek PR. A paramedic-staffed medical rehydration unit at a mass gathering. Prehosp Emerg Care 2004; 8:411.
- Wetterhall SF, Coulombier DM, Herndon JM, et al. Medical care delivery at the 1996 Olympic Games. Centers for Disease Control and Prevention Olympics Surveillance Unit. JAMA 1998; 279:1463.
- Lipman GS, Eifling KP, Ellis MA, et al. Wilderness Medical Society practice guidelines for the prevention and treatment of heat-related illness: 2014 update. Wilderness Environ Med 2014; 25:S55.
- Pryor RR, Roth RN, Suyama J, Hostler D. Exertional heat illness: emerging concepts and advances in prehospital care. Prehosp Disaster Med 2015; 30:297.
- Bytomski JR, Squire DL. Heat illness in children. Curr Sports Med Rep 2003; 2:320.
- Jardine DS. Heat illness and heat stroke. Pediatr Rev 2007; 28:249.
- Council on Sports Medicine and Fitness and Council on School Health, Bergeron MF, Devore C, et al. Policy statement—Climatic heat stress and exercising children and adolescents. Pediatrics 2011; 128:e741.
- Bergeron MF, Laird MD, Marinik EL, et al. Repeated-bout exercise in the heat in young athletes: physiological strain and perceptual responses. J Appl Physiol (1985) 2009; 106:476.
- Bar-Or O, Dotan R, Inbar O, et al. Voluntary hypohydration in 10- to 12-year-old boys. J Appl Physiol Respir Environ Exerc Physiol 1980; 48:104.
- Bar-Or O, Wilk B. Water and electrolyte replenishment in the exercising child. Int J Sport Nutr 1996; 6:93.
- Wilk B, Bar-Or O. Effect of drink flavor and NaCL on voluntary drinking and hydration in boys exercising in the heat. J Appl Physiol (1985) 1996; 80:1112.
- Wilk B, Kriemler S, Keller H, Bar-Or O. Consistency in preventing voluntary dehydration in boys who drink a flavored carbohydrate-NaCl beverage during exercise in the heat. Int J Sport Nutr 1998; 8:1.
- Inbar O, Bar-Or O, Dotan R, Gutin B. Conditioning versus exercise in heat as methods for acclimatizing 8- to 10-yr-old boys to dry heat. J Appl Physiol Respir Environ Exerc Physiol 1981; 50:406.