Heat Exposure – The Inside Story
The human body must maintain a narrow temperature range. Control mechanisms in the body adapt to changes in the environment and help regulate the body’s internal temperature. When the body is exposed to heat, blood vessels in the skin expand, bringing warm blood to the surface to be cooled. Sweat glands in the skin release fluid onto the skin surface where it evaporates, transferring heat from the blood vessels to the external environment and cooling the body in the process.
Most people readily adjust to increased temperatures. But when a body can’t regulate internal temperature, problems develop, including problems that are potentially life-threatening. This is especially the case in the workplace, where hot temperatures can combine with job-related stresses to result in serious medical conditions or even death.
There are on average 274 heat-related deaths in the United States each year, but the number is thought to be much higher.
The three main problems associated with excessive exposure to heat are the following:
- Heat cramps
- Heat exhaustion
- Heat stroke
Heat cramps are usually minor in nature. They typically result from a combination of vigorous physical activity and poor replacement of fluid to the body. Leading to dehydration- an excessive loss of water from the body. The initial affects are cramping in the leg and abdominal muscles.
Heat exhaustion, also known as heat prostration or heat collapse, is a little more serious – a mild form of shock. Shock is a potentially life-threatening condition of inadequate blood flow to the body’s tissues. It can be characterized by restlessness, anxiety, cold and clammy skin, and/or an altered level of responsiveness. Shock is the most common illness associated with heat exposure. It results from the loss of water and elements called electrolytes (elements, such as calcium and sodium, that the body uses in blood and other body fluids to conduct necessary cell functions) typically through sweating. This leads to hypovolemia, a condition of lowered fluid in the body which decreases the ability to deliver oxygen to body tissues.
The most serious heat-related illness is heat stroke. Heat stroke occurs when the body is subjected to more heat than it can handle and normal mechanisms for getting rid of excess heat, such as sweating, break down. This results in a rise in body temperature to a level at which sensitive nervous system tissue can be injured. If untreated, heat stroke can result in severe brain damage and even death.
If you suspect someone is experiencing an excessive exposure to hot temperatures, you’ll need to make a physical assessment– an examination of the patient from head to toe using eyes and hands to look and feel for signs of illness or injury.
Look and feel for the following:
- Heavy sweating
- Pale, cool, moist skin or very warm skin
- Hot, dry skin may indicate a critical emergency
- Weakness, exhaustion, dizziness
- Muscle cramps
- Diminishing level of responsiveness
Next, assess patient history (information about the patient relating to the injury or illness) by asking the patient, and/or any bystanders, about the following:
- Exposure to a hot environment or environment with high humidity
- Level of exercise and activity in environment
- Other existing medical illnesses
What do I do?
If a patient has been overexposed to high temperatures you’ll need to act quickly by following the steps below:
- Move the patient from the hot environment to a cooler location. Have the patient lie down and elevate the legs.
- As long as the patient is alert and can swallow, provide water or a diluted electrolyte solution to drink. It’s best to sip these fluids and avoid a rapid intake.
- If cramping is present, apply pressure directly on the affected area to help minimize any discomfort.
- If the patient does not quickly improve with rest or fluids, seek additional medical help.
- Provide emergency oxygen if it’s available and you are trained to use it.
When a patient’s skin temperature is extremely warm or hot and sweating is diminished or absent, a critical emergency exists and EMS should be notified immediately.
Cool the patient in any way possible. Place wet towels soaked in cold water on the patient’s bare skin. Consider placing ice bags or chemical cold packs on the patient’s armpits, groin, and neck to reduce excessive heat. Continue to cool the patient and perform ongoing assessment until help arrives. If EMS is delayed, watch the patient for overcooling. Stay calm and reassure the patient.
Prevention is Key
When you are exposed to hot environments, it is essential to take preventative measures. Whether at work, home, or play, when temperatures are high, always make sure to take precautions to prevent heat-related problems. Remember, early recognition is important. If you suspect someone is experiencing a heat-related emergency, begin treatment and activate EMS immediately. Early professional medical care is critical to a patient’s survival and potential recovery.