Which heat illness is characterized by hot, dry skin?

Heat stroke is a severe heat illness that occurs when the body becomes unable to regulate its temperature due to prolonged exposure to high temperatures or physical exertion in hot weather. One of the defining characteristics of heat stroke is the presence of hot, dry skin. This occurs because the body loses its ability to sweat, which is a critical function for cooling down. As the body's core temperature rises, sweat production diminishes, leading to dry skin despite the high environmental temperature.

In contrast, other heat illnesses present with different symptoms. For instance, heat exhaustion is typically associated with heavy sweating and a combination of weakness, dizziness, and nausea. Heat cramps involve painful muscle contractions due to electrolyte loss and generally occur during or after vigorous exercise. Heat stress is a broader term that encompasses various reactions the body can have to heat, including feelings of discomfort or fatigue without the severe symptoms seen in heat stroke. Hence, the distinguishing factor of hot, dry skin unequivocally makes heat stroke the correct answer.