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 — UpToDate
- Deputy Editor — Adult and Pediatric Emergency Medicine
- Deputy Editor — Primary Care Sports Medicine (Adolescents and Adults)
- Clinical 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 from 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 infant", section on 'Miliaria'):
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