Don't let heat get the best of you while outdoors or exercising this summer. The basics:

Heat cramp: This muscle spasm may crop up suddenly during or following intense exertion or exercise, often in the legs, causing affected muscles to painfully ball up. The usual culprit is excessive sweating that has pulled too much sodium out of the body.

To replenish lost electrolytes and prevent the cramps, drink a sports beverage such as Gatorade.

Heat exhaustion: Body temperature may be normal and blood pressure low with this heat-induced condition, also called heat prostration or heat collapse. The skin usually is cool and sweaty, and eye pupils dilated (widened). Other symptoms include weakness, dizziness, nausea and headache. Move to a cool place and put in a head-low position. If able, drink a sodium-containing beverage. Untended heat exhaustion can rapidly progress to heat stroke.

Heat stroke: Heat stroke, also known as sun stroke, is a life-threatening emergency. The core body temperature soars and sweating is absent, leaving the skin hot, dry and red. Other symptoms include headache, numbness, tingling and confusion, fast pulse, rapid breathing and possible delirium or loss of consciousness. Quick cooling is required. Call 911 for emergency medical help, then spray or sponge with cool water and fan to enhance cooling. If available, apply ice packs to the neck, armpits and groin.