Wear appropriate clothing and sunscreen. In the hot sun, a wide-brimmed hat will provide shade and keep your head cool. Sunburn affects the body's ability to cool itself and causes a loss of body fluids. It also causes pain and skin damage. Stay cool indoors.
Air conditioning is the best way to beat the heat.
If your home is not air-conditioned, consider spending a few hours in a local shopping mall or public library. Have a friend check on you at least twice a day during a heat wave.