Heat exhaustion can occur at temperatures above 90 degrees, and heat stroke can occur when temperatures rise above 105 degrees. If not treated immediately, heat exhaustion can lead to heat stroke and possibly to death.

During the summer months, the temperature inside a parked car can reach more than 120 degrees in as little as 10 minutes. Direct sunlight and a dark-colored car further speed the process. Children should never be left in a parked car, even for a few minutes and even with the windows open. Lock parked cars to prevent children from playing in them.

Heat can be dangerous to people of any age, indoors or out. To stay safe and healthy during hot weather, know the signs of heat stress and the simple things people can do—like drinking plenty of water—that can prevent heat-related illness and death.

Children, the elderly, people with chronic illnesses and people on certain medications like tranquilizers or diuretics are especially at risk from high summer temperatures. So are older people who live in homes or apartments without air conditioning or good air flow and people who don’t drink enough water. Hot weather also adds to ozone levels, making those with respiratory illness more vulnerable.

Being exposed to high temperatures for too long can cause muscle cramps, swelling in feet or ankles, or dizziness, progressing to heat exhaustion or heat stroke. Heat exhaustion, if not treated, can progress to heat stroke. Heat stroke is an emergency and requires immediate medical help—it can be fatal.

Heat exhaustion may make you feel dizzy, weak, uncoordinated, nauseated, and perhaps thirsty, and you may sweat a lot. Your skin may feel cold and clammy, although your body temperature may be normal. What to do: rest in a cool place, out of the sun; drink plenty of water or fluids (but not alcohol or caffeine); wash off with cool water if possible; and get medical care. If not treated, heat exhaustion can turn into life-threatening heat stroke.

Signs of heat stroke include fainting; a body temperature of over 104o; a change in behavior such as confusion, grouchiness, staggering or acting strangely; dry flushed skin and a strong rapid pulse or a slow weak pulse; not sweating in spite of the heat; acting delirious; slipping into a coma. What to do: call 911; get the person out of the sun and heat and have them lie down; give them plenty of water or juice to drink if they are conscious; cool their body down with a cool shower or bath or by sponging with cool water. Prompt medical attention is critical—people can die of heat stroke.

To avoid heat-related illness on hot days:

* Drink plenty of water or fruit and vegetable juices. Avoid caffeine or alcohol.

* Limit your time outdoors, especially in the afternoon when the day is hottest.

* Be careful about exercising or doing a lot of activities when it is hot. Stay out of the sun, take frequent breaks, drink water or juice often, and watch for signs of heat exhaustion or heat stroke.

* Dress for the weather. Loose-fitting, light-colored cotton clothes are cooler than dark colors or some synthetics.

* If you live in a home without fans or air conditioning, open windows to allow air flow, and keep shades, blinds or curtains drawn in the hottest part of the day or when the windows are in direct sunlight. Try to spend at least part of the day in an air conditioned place like a shopping mall, a store, the library, a friend’s house, or the movies. Cool showers can help, too. Do not use a fan when the air temperature is above 95 degrees -– it will blow hot air, which can add to heat stress.

* Never leave a child or a disabled or elderly person or a pet in an unattended car, even with the windows down. A closed vehicle can heat up to dangerous levels in as little as ten minutes.