Heat stress is a condition that occurs when the body is unable to regulate its internal temperature and cool itself through sweating. Heat stress shows many symptoms and encompasses several heat-induced illnesses such as heat stroke, heat exhaustion, heat cramps and heat rashes. These conditions are more likely to occur during hot summer months but may affect workers and athletes in various climates and conditions year-round. The most common composite measurement used to determine appropriate exposure to heat stress conditions is Wet Bulb Globe Temperature or "WBGT."