Extreme Weather and Public Health

Extreme Heat Information

Check out the Trends in Morbidity and Mortality from Exposure to Excessive Natural Heat in Arizona, 2012 Report. The report contains the latest information on natural/environmental heat-related deaths and illnesses in Arizona.

drinking water

Arizona is one of the hottest places on earth from May to September. Heat-related illnesses are common during the summer. Year after year, nearly 2,000 people visit Arizona emergency rooms because of heat-related illnesses. Some heat-related illnesses could even be fatal. Over 1,500 deaths from exposure to excessive natural heat have occurred in Arizona from 2000 to 2012. A summary of heat-related deaths and illness has been reported in the Trends in Morbidity and Mortality from Exposure to Excessive Natural Heat in Arizona, 2012 report.

As a result, the Arizona Department of Health Services has developed a Heat Emergency Response Plan, a Heat Safety Resource Guide, and a bilingual Heat Brochure. The Heat Relief Network offers tips for staying safe in the heat and Hydration and Collection maps for places to get water and donate water around Maricopa County. Get info on Tucson’s Project Summer Sun donation drive and which locations benefit from donations.

To sign up for email alerts and information regarding extreme heat warnings, check out the instructions on our Extreme Weather and Public Health homepage.

Preventing Heat-Related Illness

Your body keeps itself cool by letting heat escape through the skin, and by evaporating sweat (perspiration). If your body does not cool properly or does not cool enough, you might suffer from a heat-related illness.

Anyone can be susceptible to heat-related illness. Those at greatest risk are children under 4, adults over 65, homeless people, outdoor workers, people who are overweight, and people who are ill or on certain medications. Heat-related illness may be serious or even deadly if unattended.

Staying healthy during the summer is easier if you take the time to protect yourself by making sure you are drinking enough water and limiting your exposure to the heat. Follow these simple rules:

  • Drink water. Even people that stay mostly indoors all day should drink at least 2 liters of water per day. People that spend time outdoors should drink 1 to 2 liters per hour that they are outdoors. People that do strenuous activity outdoors should be very careful, being your body can lose up to 4 liters of water per hour during strenuous activity. You should carry water with you and drink even if you do not feel thirsty. Be heat safe and avoid alcohol and caffeine, which dehydrate the body. Avoid using salt tablets unless directed to do so by a physician.
  • Dress for the heat. Wear lightweight, light-colored clothing. Light colors will reflect away some of the sun's energy. It is also a good idea to wear hats or to use an umbrella. Always apply sunscreen to exposed skin.
  • Eat small meals and eat more often. Avoid foods that are high in protein which increase metabolic heat.
  • Slow down. Avoid strenuous activity. If you must do strenuous activity, do it during the coolest part of the day, which is usually in the morning between 4:00 a.m. and 7:00 a.m.
  • Stay indoors when possible.
  • Take regular breaks when engaged in physical activity on warm days. Take time out to find a cool place. If you recognize that you, or someone else, are showing symptoms of a heat-related illness, stop activity and find a cool place. Remember, have fun, but stay cool!

Signs & Symptoms of Heat-Related Illness

When temperatures are on the rise, watch for the following symptoms:

  • Thirst: By the time your body tells you that you are thirsty, you are already mildly dehydrated.
  • Heat cramps: Heat cramps are muscular pains and spasms due to heavy exertion. They usually involve the abdominal muscles or the legs. The loss of water and salt from heavy sweating causes heat cramps.
  • Heat Exhaustion: Heat exhaustion is less dangerous than heat stroke. It typically occurs when people exercise heavily or work in a warm, humid place where body fluids are lost through heavy sweating. Fluid loss causes blood flow to decrease in the vital organs, resulting in a form of shock. With heat exhaustion, sweat does not evaporate as it should, possibly because of high humidity or too many layers of clothing. As a result, the body is not cooled properly. Signals include cool, moist, pale, flushed or red skin; heavy sweating; headache; nausea or vomiting; dizziness; and exhaustion. Body temperature will be near normal.
  • Heat Stroke: Also known as sunstroke, heat stroke is life-threatening. The victim's temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly. Signals include hot, red and dry skin; changes in consciousness; rapid, weak pulse; and rapid, shallow breathing. Body temperature can be very high—sometimes as high as 105° F.

Stages of Heat-Related Illness

Heat-related illness usually comes in stages. The signal of the first stage is thirst. Drinking water at this stage can prevent you from progressing to the more serious kinds of heat related illnesses. The next stage is muscle cramps. These cramps can be mild or very painful. If you are caring for a person who has heat cramps, have him or her stop activity and rest. If the person is fully awake and alert, have him or her drink small amounts of cool water or a commercial sports drink. Gently stretch the cramped muscle and hold the stretch for about 20 seconds, then gently massage the muscle. Repeat these steps if necessary. If the victim has no other signals of heat-related illness, the person may resume activity after the cramps stop.

The signals of the next, more serious stage of a heat-related illness (often called heat exhaustion) include:

  • Cool, moist, pale skin (the skin may be red right after physical activity).
  • Headache.
  • Dizziness and weakness or exhaustion.
  • Nausea.
  • The skin may or may not feel hot.

The warning signs of the most serious stage of a heat-related illness (often called heat stroke or sun stroke) vary but may include:

  • Vomiting.
  • Confusion.
  • Throbbing headache.
  • Decreased alertness level or complete loss of consciousness.
  • High body temperature (sometimes as high as 105° F).
  • Skin may still be moist or the victim may stop sweating and the skin may be red, hot and dry.
  • Rapid, weak pulse.
  • Rapid, shallow breathing.
  • Seizures.

NOTE: Heat stroke is life threatening. Call 9-1-1 or the local emergency number if you are suffering from any of the above symptoms.

General Care for Heat Emergencies

General care for heat emergencies include cooling the body, giving fluids, and minimizing shock. For specific heat-related emergencies, follow these steps:

  • For heat cramps or heat exhaustion: Get the person to a cooler place and have the person rest in a comfortable position. If the person is fully awake and alert, give a half glass of cool water every 15 minutes. Do not let him or her drink too quickly. Do not give liquids with alcohol or caffeine in them, as they can make conditions worse. Remove or loosen tight clothing and apply cool, wet cloths such as towels or wet sheets or mist with water. Get the person into an air conditioned space if possible. Call 9-1-1 or the local emergency number if the person refuses water, vomits or loses consciousness.
  • For heat stroke: Heat stroke is a life-threatening situation! Help is needed fast. Call 9-1-1 or your local EMS number. Move the person to a cooler place. Quickly cool the body using any means available, including cool water and ice. If you have ice packs or cold packs, wrap them in a cloth and place them on each of the victim's wrists and ankles, in the armpits and on the neck to cool the large blood vessels. (Do not use rubbing alcohol because it closes the skin's pores and prevents heat loss.) Wrap wet sheets around the body and place the person in front of a fan or air conditioner. Watch for signals of breathing problems and make sure the airway is clear. Keep the person lying down.

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