_______ is the most severe heat illness that requires immediate medical attention.

Heat stroke is indeed the most severe heat illness and demands immediate medical attention. It occurs when the body overheats and is unable to regulate its temperature effectively, often resulting from prolonged exposure to high temperatures or vigorous physical activity in hot weather. Symptoms include a high body temperature (typically over 104°F), altered mental state or confusion, hot and dry skin (indicating the body is no longer sweating), rapid pulse, and potentially loss of consciousness.

If left untreated, heat stroke can lead to serious complications, including organ damage or death. This severity is what distinguishes heat stroke from other heat-related illnesses such as heat cramps and heat exhaustion. Heat cramps involve painful muscle spasms due to loss of electrolytes, while heat exhaustion presents symptoms like heavy sweating, weakness, and a rapid pulse; both, although concerning, are not as immediately life-threatening as heat stroke.

This understanding of the different forms of heat-related illnesses underscores the importance of recognizing the signs and seeking prompt medical intervention when heat stroke is suspected.