Final answer:
Heat stroke is the most severe form of heat illness, which is a life-threatening emergency.
Step-by-step explanation:
The most severe form of heat illness, and a life-threatening emergency, is heat stroke. Heat stroke occurs when the body's temperature regulation system fails due to prolonged exposure to high temperatures and humidity. Symptoms of heat stroke include a body temperature of 104 degrees Fahrenheit or higher, confusion, dizziness, nausea, and a rapid heartbeat.
Unlike sunburn, which is a skin condition caused by excessive exposure to ultraviolet radiation from the sun, heat stroke affects the body's core temperature. Third-degree sunburn and sun scorch are not accurate terms to describe the most severe form of heat illness.
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