• Heat Exhaustion

    What is heat exhaustion?

    Heat exhaustion occurs when fluids lost through sweating are not replaced. The body’s primary mechanism of cooling itself is through sweating. As sweat evaporates from the body, it takes body heat with it, cooling the body. If a person does not take in enough fluids, the body does not have what it needs to make adequate amounts of sweat. Humid environments and environments without good air circulation can make it difficult for the sweat to evaporate. Under these conditions, a person may develop heat exhaustion.

    Heat exhaustion is often accompanied by dehydration, as the body’s excessive production of sweat in an attempt to cool itself depletes fluid levels in the body.

    Signs and Symptoms of Heat Exhaustion

    The person’s skin will be cool and moist, and pale, ashen (gray) or flushed. The person may complain of a headache, nausea, dizziness and weakness.

    Emergency Steps

    1

    Check the scene safety, form an initial impression, obtain consent and put on PPE, as appropriate.


    2

    Check for signs and symptoms.

    • Dizziness with fainting*
    • Elevated heart rate*
    • Inability to walk or stand*
    • Nausea or vomiting*
    • Loss of appetite
    • Signs & symptoms of dehydration*
    • Fatigue
    • Heat cramps
    • Elevated respiratory rate
    • Cool, clammy, pale, ashen (gray) or slightly flushed skin
    • Weakness
    • Normal level of responsiveness

    *Note: Signs and symptoms with a * require immediate emergency medical treatment.


    3

    Call 9-1-1 and get equipment if the person requires immediate emergency medical treatment.


    4

    Give Care.


    General Care: Heat Exhaustion

    1. Move the person to a cooler environment with circulating air.
    2. Loosen and/or remove clothing.
    3. Apply cool, wet cloths to the skin or spray with cool water.
    4. Fan the person.
    5. If responsive and able to swallow, have them sip a cool electrolyte- and carbohydrate-containing fluid such as a sports drink, coconut water or milk.
      1. Offer water if these are not available.
      2. Prevent them from drinking too quickly.
    6. Have the person rest in a comfortable position.
    7. Continue checking them as appropriate to determine if additional care is needed.
    8. Give care for shock or dehydration, if necessary.
    9. Reassure person you will help and EMS has been called (if appropriate).
    10. Watch for changes in condition, including breathing and responsiveness.
    11. If condition does not improve, or if person unable to take fluids or has a change in level of responsiveness or vomits, call 9-1-1 and then give care:
      1. Stop giving fluids; place in the recovery position.
      2. Keep them lying down; continue steps to lower body temperature.
      3. Monitor for signs and symptoms of heat stroke, breathing problems or shock; give care as appropriate.
    12. Have them wait several hours after no more symptoms before resuming activity.

    Heat Exhaustion FAQs

    What are heat cramps?

    Heat cramps are painful muscle spasms, usually in the legs, arms and abdomen, caused by loss of fluids and electrolytes as a result of sweating. These cramps are possibly more common in hot and humid conditions, but they are not directly related to a rise in body temperature.

    What do I do if a person has heat cramps?

    • Stop activity and have the person rest.
    • Have them sip an electrolyte/carbohydrate drink such as a commercial sports drink, coconut water or milk. If not available, they may drink water.
    • Lightly stretch the muscle and gently massage the area.
    • Have them resume activity once the cramps stop and there are no other signs and symptoms.
    • Encourage them to keep drinking plenty of fluids.
    • Continue to monitor for additional signs and symptoms of heat-related illnesses.

    I’ve heard that I should give salt tablets to a person who is having heat cramps. Is this true?

    No, this is a myth. Salt tablets are not an effective treatment for heat cramps. Consuming a concentrated form of salt can promote loss of fluid from the body, which will make the person’s condition worse, not better.

    Are they any conditions that increase the risk of heat exhaustion?

    Yes. The first is not getting enough fluids. Heat exhaustion occurs when fluids lost through sweating are not replaced. The body’s primary mechanism of cooling itself is through sweating. As sweat evaporates from the body, it takes body heat with it, cooling the body. If a person does not take in enough fluids, the body does not have what it needs to make adequate amounts of sweat. Heat exhaustion is often accompanied by dehydration.

    Also, humid environments and environments without good air circulation can make it difficult for the sweat to evaporate. Under these conditions, a person may develop heat exhaustion.

    What environmental temperature is most likely to cause a heat-related illness? Are there other risk factors besides temperature?

    Environmental temperatures that are greater than 100° F (38° C) increase risk. However, if someone is unaccustomed to labor or exercise in the heat, they can develop a heat-related illness at lower environmental temperatures. Other factors, such as humid air, inadequate fluid intake, heavy clothing and personal characteristics (e.g., the presence of certain medical conditions, taking certain medications and the person’s age, especially older adults and young children and infants) can increase the risk for heat-related illness.

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