Heat Exhaustion usually develops after several days of exposure to high temperatures and inadequate intake of fluids. Heat exhaustion symptoms include heavy sweating, paleness, muscle cramps, tiredness, weakness, dizziness, headache, nausea, vomiting, and/or fainting. With heat exhaustion, a person's skin may feel cool and moist.
Cooling off is the main treatment for heat exhaustion. Drinking cool, non-alcoholic liquids may help as well as taking a cool shower, bath, or sponge bath. If the conditions worsen or have not subsided within an hour, seek medical attention.
Heatstroke is the most severe of the heat-related problems. Like heat exhaustion, it often results from exercise or heavy work in hot environments combined with inadequate fluid intake. Children, older adults, obese people, and people who do not sweat properly are at high risk of heatstroke. Other factors that increase the risk of heat stroke include dehydration, alcohol use, cardiovascular disease and certain medications. Heatstroke is life-threatening because the body loses its ability to deal with heat stress. It can't sweat or control the body's temperature. Symptoms of heatstroke include rapid heartbeat, rapid and shallow breathing, elevated or lowered blood pressure, lack of sweating, irritability, confusion or unconsciousness, feeling dizzy or lightheaded, headache, nausea, and/or fainting. If you suspect heatstroke, call 9-1-1 immediately.
—Thad McLaurin