Heat Related Illness

Heat Exhaustion and Heatstroke: What You Need To Know

What causes heat exhaustion and heatstroke?

Heat-related illnesses, such as heat exhaustion and heatstroke, occur when your body can't keep itself cool. As the air temperature rises, your body stays cool when your sweat evaporates. On hot, humid days, the evaporation of sweat is slowed by the increased moisture in the air. When sweating isn't enough to cool your body, your body temperature rises, and you may become ill.

What is heat exhaustion?

Heat exhaustion happens when your body gets too hot. It can be caused by exercise or hot weather. You may feel weak, dizzy or worried. You also may have a headache or a fast heartbeat. You may get dehydrated and have very little urine.

What should I do if I think I have heat exhaustion?

If you think you have heat exhaustion, get out of the heat quickly. Rest in a cool, shady place. Drink plenty of water or other fluids. Do NOT drink alcohol. Alcohol can make heat exhaustion worse. If you do not feel better within 30 minutes, you should contact your doctor. If heat exhaustion is not treated, it can progress to heatstroke.

What is heatstroke?

Signs of heat-related illness

• Weakness
• Headache
• Dizziness
• Muscle weakness or cramps
• Nausea and vomiting
• Worried feeling
• Fast heartbeat
• Dehydration

Heatstroke can happen when your body gets too hot, or it can happen after heat exhaustion. Heatstroke is much more serious than heat exhaustion. Heatstroke can kill you. People with heatstroke may seem confused. They may have seizures or go into a coma. Most people with heatstroke also have a fever.

What should I do if I think someone has heatstroke?

If you think someone might have heatstroke, you should take him or her to a cool, shady place quickly, and call a doctor. Removing the person's unnecessary clothing can help cool him or her down. Try to fan warm air over the person while wetting the skin with lukewarm water. This will help the person cool down.

Get medical help right away if you have these warning signs:

• Skin that feels hot and dry, but not sweaty.
• Confusion or loss of consciousness.
• Frequent vomiting.
• Shortness of breath or trouble breathing.

Do medicines affect heatstroke?

The following are some medicines that can put you in danger of heatstroke:

• Allergy medicines (antihistamines)
• Cough and cold medicines (anticholinergics)
• Some blood pressure and heart medicines
• Diet pills (amphetamines)
• Irritable bladder and irritable bowel medicines (anticholinergics)
• Laxatives
• Some mental health medicines
• Seizure medicines (anticonvulsants)
• Thyroid pills
• Water pills

Tell your doctor what medicines you are taking. He or she can tell you if your medicine puts you in danger of heatstroke.

What does the "heat index" mean?

The heat index tells you how hot it feels outside in the shade. It is not the same as the outside temperature. The heat index is a measurement of how hot it feels when relative humidity is combined with the effects of the air temperature. When you are standing in full sunshine, the heat index value is even higher. A heat index of 90° or above is dangerous.

How can I prevent heat illness?

When the heat index is high, stay indoors in air-conditioned areas when possible. If you must go outside, take the following precautions:

• Wear lightweight, light-colored, loose-fitting clothes.
• Protect yourself from the sun by wearing a hat or using an umbrella.
• Use sunscreen with a sun protection factor (SPF) of 15 or more.
• Drink plenty of water before starting an outdoor activity. Drink extra water all day. Drink fewer beverages that contain caffeine (such as tea, coffee and cola) or alcohol.
• Schedule vigorous outdoor activities for cooler times of the day--before 10 a.m. and after 6 p.m.
• During an outdoor activity, take frequent breaks. Drink water or other fluids every 15 to 20 minutes, even if you don't feel thirsty. If you have clear, pale urine, you are probably drinking enough fluids.
• If you have a chronic medical problem, ask your doctor about how to deal with the heat, about drinking extra fluids and about your medicine

What should I do after having heat exhaustion or heatstroke?

Having heat exhaustion or heatstroke makes you more sensitive to hot conditions for about a week afterwards. Be especially careful not to exercise too hard, and avoid hot weather. Ask your doctor to tell you when it is safe to return to your normal activities.