Healthcare BLS + First Aid

73 videos, 5 hours and 32 minutes

Course Content

Heat-Related Emergencies

Video 65 of 73
3 min 40 sec
English, Español
English, Español

As you know, the human body runs at an internal temperature of 98.6 degrees Fahrenheit, or 37 degrees Celsius.

The control center responsible for regulating this internal temperature is located in the brain, and more specifically, the hypothalamus. The hypothalamus receives information and adjusts body functions to maintain this optimal temperature.

The temperature range – that which allows cells to stay alive and healthy – is actually quite narrow, at between 97.8 degrees and 99 degrees.

Let's quickly look at the process of how the body cools down on its own.

  • The hypothalamus detects a rise in blood temperature.
  • Blood vessels close to the surface of the skin begin to dilate.
  • This brings more blood to the surface and allows heat to escape.

At the end of this lesson, we'll get into the five general ways in which the body can be cooled externally, along with several types of heat-related conditions to watch out for.

How to Treat for a Heat-Related Emergency

Heat-related emergencies typically occur in hot environments and when the patient hasn't been rehydrating enough to compensate for water loss. Common symptoms of a heat-related emergency include:

  • Profuse sweating
  • Dizziness
  • Extreme thirst
  • Cramping, usually in arms or legs

Warning: Losing fluids can be very serious. In the absence of proper medical treatment, if the condition cannot be reversed, it will likely progress to the next level which is heatstroke.

Pro Tip #1: If the patient suddenly goes from wet to dry and stops sweating, it's because the patient's body doesn't have enough fluids to lose. This is a good indication that the warning above is now likely a reality, making the situation that much more serious.

Your number one goal when dealing with a heat-related emergency is to cool the patient down any way you can.

Ideally, the patient is able to get some fluids down. But if for some reason they aren't able to drink or swallow or can't hold fluids down, you'll need to cool them off externally.

Find a water source and some containers or a hose and begin pouring water over the victim, including their clothing, to help bring their core temperature down to a safe level.

Another great aid in these situations is the cold pack. If you have some available, try placing them under the patient's armpits, the back of the neck, or forehead.

Pro Tip #2: The key to successfully treating someone who is having a heat-related emergency begins by recognizing that emergency. Time is crucial. Once you've diagnosed the problem, the next step is reversing the condition by cooling them down.

If at any point, the patient becomes unresponsive, goes unconscious, or is not able to breathe normally, call 911 immediately and activate EMS. Then begin CPR.

A Word About Heat-Related Emergencies

There are several types of heat-related conditions to be aware of, but let's first look at the general ways in which the body can be cooled.


Radiation involves the transfer of heat from one object to another, though without physical contact. The human body also loses heat due to radiation, mostly through the head, feet, and hands.


Convection occurs when cold air moves over the skin and carries heat away. The faster the flow of air, the faster the body will be cooled. Convection is why warm skin feels cooler in a breeze. Convection also assists in the evaporation process.


Conduction occurs when the body is in direct contact with something that is cooler than the body's temperature. Conduction allows the body's heat to transfer to the cooler object. Think about swimming in a cold lake or leaning against a cool slab of stone.


Evaporation is the process by which a liquid or solid becomes a vapor. When body heat causes one to perspire and the perspiration evaporates, the heat that was absorbed into the sweat dissipates into the air which cools off the skin.


The last way in which the body can cool itself is through respiration. Before air is exhaled, it's warmed by the lungs and airway. Respiration accounts for around 10 to 20 percent of heat loss.

There are several types of heat-related illnesses (hyperthermia) to be aware of, including dehydration, exercise-associated muscle cramps, exertional heat exhaustion, and heatstroke.


Dehydration occurs when there is an inadequate supply of water in the body's tissues. Dehydration can be serious and life-threatening, particularly for the very young and very old. Symptoms, which include fatigue, headaches, irritability, nausea, and dizziness, will worsen as the body continues to lose water.

Exercise-Associated Muscle Cramps

Muscle cramps are thought to occur due to a combination of fluid and electrolyte loss through sweating. Muscle cramps typically come on quickly and after rigorous work or exercise and are particularly more common in warmer environments.

Exertional Heat Exhaustion

Exertional Heat Exhaustion occurs when the body loses more fluids than are replenished. As this happens, the body will divert blood from the surface of the body to vital organs like the heart and brain. This type of heat-related illness is usually the result of intense physical activities and often in hot and humid climates – athletes, firefighters, construction workers, etc.


Heatstroke is the most serious type of heat-related illness and can be life-threatening if quick action isn't taken. As there is a progressive nature to these conditions, ignoring the warning signs of exertional heat exhaustion can quickly lead to a body that will become overwhelmed by heat and begin to stop functioning.