Heat emergencies occur when heat pushes the human body beyond its physical limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.

[edit] Steps

Stay indoors as much as possible and limit exposure to the sun.
Stay on the lowest floor out of the sunshine if air conditioning is not available.
Consider spending the warmest part of the day in public buildings such as libraries, schools, movie theaters, shopping malls, and other community facilities. Circulating air can cool the body by increasing the perspiration rate of evaporation.
Eat well-balanced, light, and regular meals. Avoid using salt tablets unless directed to do so by a physician.
Drink plenty of water. Persons who have epilepsy or heart, kidney, or liver disease; are on fluid-restricted diets; or have a problem with fluid retention should consult a doctor before increasing liquid intake.
Limit intake of alcoholic beverages.
Dress in loose-fitting, lightweight, and light-colored clothes that cover as much skin as possible.
Protect face and head by wearing a wide-brimmed hat.
Check on family, friends, and neighbors who do not have air conditioning and who spend much of their time alone.
Never leave children or pets alone in closed vehicles.
Avoid strenuous work during the warmest part of the day. Use a buddy system when working in extreme heat, and take frequent breaks.
Take a 1 liter or a 2 liter bottle, fill it full of water, place it in a freezer until frozen, then place it in a medium to large bowl, get a fan (preferrably solar powered, since a heat wave, heat storm will cause power to fail) and let it blow all over the bottle in the bowl. the bowl is to catch condensation, while you get cool air.

[edit] Warnings

Drought can affect vast territorial regions and large population numbers. Drought also creates environmental conditions that increase the risk of other hazards such as fire, flash flood, and possible landslides and debris flow.
An emergency water shortage can be caused by prolonged drought, poor water supply management, or contamination of a surface water supply source or aquifer.
A heat wave, heat storm can cause power failures via overloading the power systems.
Check to see if YOUR area has any "Drought Regulations" in effect, otherwise even watering the lawn, cooling yourself can land you a hefty fine, even jail time.