EPHT – Hyperthermia | Missouri Department of Health and Senior Services

Hyperthermia (also known as heat-related illness or heat stress) happens when hot weather or other heat exposure causes body temperature to rise above normal. Heat-related illness is dangerous and can quickly become life threatening. The Missouri Environmental Public Health Tracking (EPHT) Program shares data on heat-related illness and deaths in Missouri.

Be Safe, Aware, And Prepared for Hot Weather

Each year many Missourians suffer from heat-related illness, with some cases resulting in death. During prolonged periods of high temperatures, it's best to stay indoors – either at home in air conditioning or by seeking shelter in a local cooling center.

Don't Wait, Call 911

If someone has signs of heat-related illness -- like fainting, confusion, high body temperature (103F or more), hot dry or damp skin, fast pulse, nausea or vomiting, or seizure.

Protect Adults in Need

Report older adults and adults with disabilities in need of assistance due to hot temperatures. You can make a report online or call the state's toll-free number 1-800-392-0210 anytime.

Report Online

Community Resources

Cooling Centers Map

Find a place to cool down during the day.

For overnight shelter, contact local emergency management or call United Way 2-1-1.

Utility Assistance

Get help with home energy costs, if you or someone you know is in need.

Extreme Weather Toolkit

Community template response plan, resources, checklists, communications and best practices in responding to extreme heat.

Symptoms of Heat-Related Illness & What to Do

What to Look For in a Person

What to Do for a Person

Heat Stroke

High body temperature (103°or higher)

Hot, red, dry skin

Fast, strong pulse

Headache

Dizziness

Nausea

Confusion

Fainting (passing out)

Call 911 right away – heat stroke is a medical emergency

Move them to a cool or shady place

Cool them down using any method you can: a cool bath or shower; spray of cool water from a garden hose; cool wet cloths; or cool sponge

Do not give them anything to drink

Avoid use of fans

Heat Exhaustion

Heavy sweating

Cool, pale and clammy skin

Muscle cramps

Tiredness or weakness

Fast, weak pulse

Headache

Dizziness

Nausea or vomiting

Fainting (passing out)

Move them to a cool place

Loosen their clothing

Cool them down with a cool bath or shower; cool wet cloths; or cool sponge

Give them cool water to drink

Call 911 immediately if:

Vomiting

Symptoms get worse

Symptoms last longer than 1 hour

Heat Cramps

Heavy sweating during intense exercise

Muscle pain or spasms

Stop physical activity and move them to a cool place

Give them water or a sports drink

Advise them to wait for cramps to go away before returning to physical activity

Call 911 immediately if:

Cramps last longer than 1 hour

They are on a low-sodium diet

They have heart problems

Tips for Staying Safe

Be aware of the warning signs of heat-related illness and what to do.

Air Conditioning

Stay indoors in air-conditioning as much as possible and limit exposure to the sun.
If air conditioning isn't available, spend the warmest part of the day in a library, school, supermarket, movie theater, shopping mall, friend or neighbor's house, senior center, or other air-conditioned location.

Water, Food and Medicine

Drink plenty of water - regardless of your activity level. Don't wait until you feel thirsty to drink fluids. Ensure infants and children drink adequate amounts of liquids.
- Avoid drinks containing caffeine, alcohol, or large amounts of sugar because they can cause you to lose more fluid.
- Individuals with epilepsy or heart, kidney, or liver disease, who are on fluid-restricted diets, or who have problems with fluid retention should consult a doctor before increasing liquid intake.
Eat light, well-balanced meals at regular intervals.
Ask your doctor whether medications you take affect your body's response to the heat.

Clothing

Dress in loose-fitting, lightweight, and light-colored clothes that cover as much skin as possible.
When outdoors, protect your face and head by wearing a wide-brimmed hat.
Wear sunscreen. Sunburn affects your body's ability to cool itself.

Outdoor Activity

Schedule outdoor activities when it's coolest, in the morning or evening.
Slow down and avoid strenuous activity during the warmest part of the day.
Take frequent breaks in a cool or shady place.

Check on Others

Check regularly on friends, family, and neighbors at greatest risk of heat-related illness:
- infants and children up to 4 years of age
- people 65 years of age or older
- people who are overweight
- people working or exercising outdoors
- people who are ill or on certain medications
Use the buddy system when active or working in extreme heat.
Never leave children or pets alone in a parked car or other hot environment.

Do fans help?

Keep Skin Moist

In order for a fan to be effective, a person's skin must be moist. When the skin surface is moist, moving air removes heat from the skin as the moisture evaporates. Unfortunately, when a person begins to develop heat stroke, they stop sweating. Elderly people may not sweat due to loss in their ability to regulate their body temperature. If a fan is to be effective, the skin must be moist either with sweat, by wearing dampened clothing, or by rubbing a wet cloth over the skin.

When Not to Use Fans

Fans may be harmful when temperatures are very high. As the air temperature rises, air flow is increasingly ineffective in cooling the body until finally, at temperatures above 100° F or so (the exact number varies with the humidity), increasing air movement actually increases heat stress. More specifically, when the temperature of the air rises to about 100° F, a fan may be delivering overheated air to the skin at a rate that exceeds the capacity of the body to get rid of this heat, even with sweating, and the net effect is to add heat rather than to cool the body. The best thing to do when temperatures soar is to use an air conditioner, if one is available, or seek shelter in an air-conditioned building.

Tips for Keeping Your Home Cool

Keep your house closed during the hottest part of the day. Check indoor and outdoor thermometers to make sure that the indoor temperature remains cooler than outdoors.
Open all windows early in the morning and on cooler nights to get rid of heat.
Use floor and ceiling fans as much as possible to circulate a cooling breeze. Also use window fans if not using air conditioning.
Use appliances and equipment that give off heat (iron, light bulbs, clothes dryer, hair dryer, etc.) only as needed and limit use to the early morning or at night, not during the middle of the day.
Install window air conditioners snugly; insulate spaces around the air condition for a tighter fit, if necessary.
If you have central air conditioning, set the thermostat no lower than 78 degrees.
Check air-conditioning ducts for proper insulation.
Change or clean your air-conditioner filter often.
Cover windows that get morning or afternoon sun with drapes, shades, awnings, or louvers.
Install temporary window reflectors (for use between windows and drapes), such as aluminum foil-covered cardboard, to reflect heat back outside.
Weather-strip doors and window sills to keep cool air in.
Keep storm windows up all year.

Heat Hazard Terms

Heat Wave is a prolonged period of excessive heat, often combined with excessive humidity.

Heat Index is a number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.

Heat Cramps are muscle pains and spasms from heavy exertion in the heat. Heat cramps are often a first sign the body is having trouble with the heat.

Heat Exhaustion is a mild form of shock that happens when body fluids are lost and blood flow increases to the skin, causing blood flow to decrease to the vital organs. Most at risk are elderly people, people with high blood pressure, and people working or exercising in a hot environment, where body fluids are lost through heavy sweating. If not treated, a person's condition will worsen. Body temperature will keep rising and the person may suffer heat stroke.

Heat Stroke is a life-threatening condition. The person'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.

Sun Stroke is another term for heat stroke.

Announcements

Get the Facts | From 2010 - 2025, there were 370 heat-related deaths in Missouri.

Announcements

Get the Facts | From 1998 - 2025, 26 children died of heatstroke in a hot vehicle in Missouri.

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Hyperthermia Data

Heat-Related Illness Data

• Missouri EPHT – Heat-Related Illness Query

Search this query to find:

Annual numbers of emergency department visits and hospitalizations

Annual crude rates of emergency department visits and hospitalizations, per 100,000 residents

Annual age-adjusted rates of emergency department visits and hospitalizations, per 100,000 residents

Heat-Related Death Data

• Missouri EPHT – Environmental Comparisons Profile – Heat-Related Deaths

Heat & Health Tracker

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The National Environmental Public Health Tracking Program

Missouri Environmental Public Health Tracking (EPHT) is a program within the Missouri Department of Health and Senior Services and funded by the Centers for Disease Control and Prevention. EPHT is part of a network of people and information systems which delivers a core set of health, exposure, and hazards data, information summaries and tools to enable analysis, visualization and reporting of insights drawn from data. Those insights are intended to help data drive actions and improve community health.

EPHT – Hyperthermia

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Related Links

Be Safe, Aware, And Prepared for Hot Weather

Community Resources

Cooling Centers Map

Utility Assistance

Extreme Weather Toolkit

Announcements

Announcements

Hyperthermia Data

Heat-Related Illness Data

Heat-Related Death Data

Heat & Health Tracker

Melanoma Dashboard