Athletes who compete in endurance sports may sustain exercise-associated collapse (EAC) during or after an event. A classification system was devised for EAC that can be used by physicians who cover endurance events. Symptoms and signs of EAC include exhaustion, nausea, cramps, abnormally high or low core body temperature, muscle spasms, and inability to walk unassisted. The three classes of EAC are hyperthermic, normothermic, and hypothermic; each class is subclassified as mild, moderate, or severe. Treatment of warm runners includes applying ice bags wapped with wet towels to the major areas of heat loss (neck, axilla, groin) to lower the core body temperature. Treatment of cool runners involves removing wet clothing, drying the skin, and insulating with wool blankets.