With an increasing number of children and adolescents involved in competitive athletics throughout the calendar year, the sports medicine team must be familiar with preventing and treating heat-related illness. Heat illness is a spectrum of illnesses from heat cramps to heat stroke. Mortality for heat stroke ranges from 17% to 70%, depending on severity and age of the patient. Children are more susceptible to heat illness than adults for many reasons, including a greater surface area to body mass ratio, lower rate of sweating, and slower rate of acclimatization. The prevention of heat illness is based on recognizing and modifying risk factors, which include environmental conditions, clothing, hydration, and acclimatization. Once heat illness is suspected, treatment should begin immediately with rapid cooling procedures started on the field.