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Heat Illness

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Heat Illness

Summer weather means getting outside and having fun or working in the yard, but too much heat can make you sick.1 Heat waves are the leading cause of extreme weather-related deaths in the United States.2 Michigan had 1,882 emergency department visits for heat-related illness in 2018 the most recent year data are available (MiTracking Data Portal). Average temperatures are predicted to rise by 3-6°F in the Great Lakes region by the year 2050.3 This could cause more extreme heat events and heat-related illnesses.  

Heat Illness data for emergency department visits and hospitalizations are available on the MiTracking data portal.

  • Your body normally cools itself as your sweat evaporates. But during some extremely hot weather conditions, sweating isn't enough to cool you. Hot weather conditions can make your body temperature dangerously high, possibly leading to illness or even death.1

    For more information, visit Michigan Prepares - Extreme Heat.

  • Those at highest risk include4:

    • People older than 65
    • Outdoor workers
    • Low-income individuals and families
    • Infants and children
    • People who live alone
    • People without air conditioning
    • People who exercise outside
    • People with chronic conditions (e.g., diabetes, cardiovascular disease, and respiratory disease)


    For more risk factor information, visit CDC - About Extreme Heat.

  • Heat-related illnesses are preventable. Below are signs of heat-related illnesses. Some conditions like heat rash and sunburn are less severe than heat exhaustion and heat stroke. If you suspect you or someone is experiencing a heat stroke, call 911 immediately.5

    Heat Rash

    Red cluster of pimples or small blisters most likely to occur on the:

    • Neck
    • Upper chest
    • Groin
    • Under the breasts
    • In elbow creases



    Red, painful skin, sometimes with blisters


    Heat Cramps

    • Heavy sweating
    • Muscle pain


    Heat Exhaustion

    • Heavy sweating
    • Cramps
    • Fatigue
    • Weakness
    • Headache
    • Cool and moist skin
    • Fast and weak pulse
    • Faint breathing
    • Nausea
    • Fainting


    Heat Stroke

    • Skin that feels hot and dry but not sweaty
    • Body temperature above 103°F
    • Rapid, strong pulse
    • Headache
    • Nausea
    • Confusion
    • Dizziness
    • Unconsciousness


    For more heat-related treatment information, visit CDC - Tips for Preventing Heat-related Illnesses.

  • Even short periods of high temperature can cause serious, and sometimes life-threatening, health problems. Talk with your doctor about how your chronic medical conditions or medication will be affected by heat. These are steps you can take to avoid heat illness when it's hot outside.6


    Stay Cool

    • Wear lightweight, light-color, loose fitting clothes.
    • Stay indoors. Go to your local shopping mall or library. Call your local health department about heat-relief shelters.
    • Limit outdoor activity to the morning and evening hours when it's not as warm.
    • Cut down on exercise during heat events.
    • Wear sunscreen with an SPF of 15 or higher, and that says "broad spectrum" or "UVA/UVB protection" on the label.
    • Never, ever leave anyone or pets in a closed, parked car.
    • Keep meals light and cool.


    Stay Hydrated

    • Drink lots of water when it's hot, even when you are not thirsty.
    • If your doctor limits the amount of fluid you drink or if you are taking water pills, ask your doctor how much you should drink when the weather is hot.
    • Stay away from sugary, caffeinated, and alcoholic drinks. These cause you to lose fluid.
    • Make sure your pets have fresh water available at all times.


    Stay Informed

    • Check with your local news and active alerts for updates.
    • Learn about heat illness and symptoms (see Illnesses and Symptoms section above).
    • Check on family members, neighbors, or friends that are confined to their home at least twice a day. Move them to a cool place if necessary.
    • Know who is most at risk (see Risk Factors section above).

    For more information, visit CDC - Hot Weather Tips.

  • Heat Illness MiTracking Indicators

    • Emergency department visits
    • Hospitalizations due to heat illness


    MiTracking Data Can Tell Us

    • The numbers of reported ED visits and hospitalizations for heat illness.
    • The crude rate of ED visits or hospitalization for heat illness.
    • The age-adjusted rate of ED visits or hospitalization for heat illness.
    • If heat-related ED visits or hospitalizations are going up or down over time.


    MiTracking Data Cannot Tell Us

    • The total number of people who are affected by heat illness.
    • The cost, effect, result, or consequence of heat illness.


    Find Out More

    The hospitalization dataset was created from the Michigan Inpatient Database (MIDB). The emergency department visits dataset was processed and created using data from the Michigan Outpatient Database (MODB) and the MIDB obtained with permission from the Michigan Health and Hospitalization Association (MHA) Service Corporation. For more data information, visit:

    1. Michigan Prepares. Extreme Heat. MDHHS website. Accessed July 8, 2022.
    2. National Center for Environmental Health. CDC's Tracking Network in action: extreme heat. CDC website. Accessed July 8, 2022.
    3. GLISA. Temperature. Accessed July 8, 2022.
    4. CDC. Protecting disproportionately affected population from extreme heat. Accessed July 8, 2022.
    5. MDHHS. Surviving Michigan summer heat: keeping your cool when it's hot outside. Accessed July 8, 2022.
    6. CDC. Natural disasters and severe weather: hot weather tips. Accessed July 8, 2022.