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Heat Exhaustion: Signs, Risks, and Tips to Avoid It

Evidence-based Reviewed Article

An image of a woman holding her temple with her eyes closedApproximately 1,300 people may die in the United States every year due to exposure to high temperatures.1 And this number does not include people dying of pre-existing health issues to which heat could have been a contributing factor. A good example of this is heart attacks. Heat exhaustion may promote the incidence of heart attacks because the heart needs to work harder during warm weather to keep down the body’s core temperature. Warmer weather also puts an added strain on the kidneys and lungs. People with a history of heart disease may see an increased risk of heart attack during the warm summer months.2 So what is your risk of heat exhaustion, and what can you do to prevent it?

Heat exhaustion results from a body unable to cool itself. While hot weather and exercise may push up your body’s core temperature, alcohol use and dressing too warmly in clothes that hamper your body’s ability to sweat or for sweat to evaporate also play a role.

There are four heat-related conditions. We will explore them from least to most severe and look at other heat-related conditions people may develop.

1) Heat Cramps

Developing heat cramps, or muscle cramping as it is also known, is one of the first signs that point to the development of heat exhaustion. Your muscles may ache and cramp up, or it may feel as if you have pulled a muscle. You may also experience pain, thirst, and fatigue during this time. Dehydration symptoms may also occur.

2) Heat Syncope

The term syncope refers to fainting. Your body, when it tries to cool itself, will experience dilated blood vessels. This, in turn, may result in reduced blood flow to the brain. This could result in fainting.

Other symptoms of heat syncope include feelings of nausea, dizziness, and restlessness. You may also develop tunnel vision, experience a drop in pulse rate, become pale, and sweat a lot.

People usually develop heat syncope due to physical activity like yard work, for example, when it is hot outside.

3) Heat Exhaustion

The next stage, heat exhaustion, is marked by an excessive loss of salt and water. This usually results from profuse sweating due to the body overheating in high temperatures. It is most common when you have high humidity combined with high temperatures while doing strenuous physical activities.

Symptoms associated with heat exhaustion include the following:

  • Dehydration resulting from heavy sweating
  • Headache
  • Excessive fatigue
  • A drop in blood pressure levels
  • A marked change in your pulse rate
  • Weakness
  • Skin feeling cold and clammy
  • Dizziness or fainting
  • Coordination issues
  • Nausea
  • Vomiting

4) Heat Stroke

If you do not address heat exhaustion, you can develop heat stroke. This is the most serious heat-related issue. You should treat heat stroke as a medical emergency. Failure to do so could result in organ damage, brain damage, or even death.

The most common heat stroke symptoms include the following:

  • An image of a hand checking the pulseA very rapid pulse rate
  • Low blood pressure levels
  • Dehydration
  • You either stop sweating or sweat very little although it is hot
  • Skin may feel hot and dry
  • Body temperature rises above 1030F
  • Severe headache
  • Extreme fatigue
  • Nausea
  • Vomiting
  • Muscle cramps
  • Muscle weakness
  • Urine becomes dark in color
  • Deliriousness
  • Behavior becomes bizarre
  • Become confused and/or disorientated
  • Lose consciousness
  • Fall into a coma

Please note that up to twenty percent of people who have had heat stroke develop brain damage that can affect their quality of life. This is because your nervous system, particularly nerve cells, becomes vulnerable when exposed to high heat.

Other Heat-Related Conditions

Heat rash and rhabdomyolysis are two other health issues you could develop when exposed to high temperatures.

Heat rash, a skin irritation, could result from sweating a lot during hot, humid weather conditions. It can look like a red cluster of small pimples or blisters, usually in the groin area, elbow creases, neck, upper chest, and under breasts.

Rhabdomyolysis is a condition that may arise when you have heat exhaustion or heat stroke. It is associated with heat stress and physical exertion. This can lead muscle tissue to break down and die. At the time, electrolytes and large proteins enter the bloodstream. This could cause a variety of issues such as seizures, kidney damage, and an irregular heart rhythm. It could have a debilitating effect on health and even lead to death. The most common symptoms of rhabdomyolysis include severe muscle cramps, constant feelings of weakness, and very dark urine.

The Risk Factors for Heat Exhaustion

While anyone stands a risk of heat exhaustion, certain things can increase your risk.


Young children and older adults have a higher risk of heat exhaustion. The ability of a body to self-regulate temperature develops at around one and a half to two years of age. This makes babies and toddlers very susceptible to temperature changes. Older adults, those over 65 years of age, tend to have various health issues and regularly make use of medications. Many of them use medications for chronic health conditions. These health issues, medications, or other factors related to aging can affect their ability to self-regulate body temperature.


Some medications may promote dehydration or reduce your body’s ability to properly respond to heat. Examples of these medications include blood pressure medications, antihistamines, antipsychotics, and diuretics. Certain drugs, especially illegal ones like amphetamines, can actively increase your body’s core temperature.


High temperatures combined with humidity means your body has trouble cooling itself. This is because humidity in the air stifles the evaporation of sweat. This could make it easier for you to develop heat exhaustion and even heat stroke.

Sudden Changes In Temperature

Your body needs time to adjust to changes in climate. If you are someone used to a cooler climate and suddenly go somewhere with a warm climate, you increase your risk of heat exhaustion and other heat-related issues.


Fat acts as an insulator. In other words, it reduces your body’s ability to deal with heat. This means that obese people have a greater susceptibility to heat exhaustion than leaner people.5

Chronic Stress and Heat Exhaustion

An image of a man leaning on a fenceVery high temperatures can act as a stressor on your body and can interact with chronic stress-related conditions like adrenal fatigue.

Your body’s NeuroEndoMetabolic (NEM) stress response kicks in to manage stress, releasing neuroendocrine hormones like cortisol, cytokines, and human growth hormone.4 This NEM stress response is designed to help your body deal with stress and support your immune response. However, when your adrenal glands start pumping out cortisol in high quantities for long periods, you may end up with a hormone imbalance. This affects the hormones and neurotransmitters in your brain that play a role in sleep and overall mental function.

If this call for increased cortisol production extends for a significant period, you could end up with adrenal fatigue. Adrenal Fatigue Syndrome (AFS) is the non-Addison's form of adrenal dysfunction, where the body's stress response cannot keep up with life's chronic stressors and the demand for cortisol. The result is a lower-than-normal production of cortisol with its own set of debilitating consequences.

Furthermore, your body’s detoxing organs may also become affected when subjected to heat stress and AFS. The skin and liver play an important function in getting rid of toxins. Your body eliminates toxins by sweating and when urinating. However, profuse sweating associated with heat exhaustion could put added stress on a body already in a state of stress, in effect worsening adrenal fatigue. Those with adrenal fatigue find that they also have a harder time regulating temperatures, so they're very sensitive to the heat or to the cold.

Addressing Heat Exhaustion and Other Heat Issues

If you show any signs of heat-related issues, the first thing to do is to get out of the heat if possible and rehydrate. This means taking regular sips of cool water, a sports drink, or even a rehydration drink. While all will help with dehydration, the latter two may help to introduce electrolytes into your body which can be lost through sweat.

Other things you could try:

  • Wet the person’s skin
  • Soak their clothes in cool water
  • Place a wet cloth on the skin, especially the neck area
  • Get them into an area where air circulates
  • Remove shoes, socks, and other unnecessary clothes
  • Have them checked for rhabdomyolysis if their urine is dark
  • Have them lie down
  • In case of a heat rash, keep the area dry and apply powder to promote comfort
  • Get the person medical help as soon as possible if you suspect heat exhaustion or heat stroke

Do NOT give them salt tablets. DO get medical help immediately if the affected person has a heart issue, has continuous cramps, or follows a diet low in salt.

Also, remember that you don't need to avoid the sun completely to avoid heat exhaustion. Some sun exposure is necessary. The sun is our primary source of vitamin D. In fact, many suicidal people have low vitamin D levels with a pro-inflammatory status in their blood.3 So, you do need some sun exposure. Not hours, though.

If you have adrenal fatigue, do your best to avoid temperature fluctuations during the summer and try your best to not over-exert yourself. Also, try and keep cool so that you do not sweat too much. Anyone at risk of developing heat exhaustion could also consider taking a supplement like Mag Three. This supplement has a calming effect on both body and mind and may have a positive effect on adrenal health. This applies to people with adrenal fatigue, those who lead stressful lives, and even those at risk of heat-related health issues.

However, please talk to your healthcare provider before self-medicating or using natural supplements. They may affect medications you may use or have an unexpected influence on pre-existing health issues.

In Closing

An image of a woman wiping her foreheadHeat exhaustion and its related heat conditions could have a long-term effect on your body. Not only could it affect the function of certain organs but influence brain health as well. You should thus take any heat-related issue seriously. In the case of especially heat exhaustion, heat stroke, and rhabdomyolysis, please ensure the affected person gets medical attention as soon as possible. Not doing so could lead to serious health issues or even death.

The best way to prevent heat exhaustion is to dress as coolly as possible, always stay hydrated, and limit your exposure to extreme heat. This is especially the case if you work in a hot, humid environment, exercise when it is hot, or come from a cooler climate and have not yet acclimatized to your new surroundings.

While prevention is paramount, immediate action is necessary if you suspect heat-related issues. However, for those experiencing persistent heat intolerance possibly linked to adrenal fatigue, Dr. Lam's Adrenal Fatigue Recovery Program offers a comprehensive solution.

This program provides guidance on diet, meditation, exercise, and supplementation for natural recovery, without the need for doctor visits, costly tests, or prescriptions. With Dr. Lam's personal experience and expertise, this program offers a structured approach to overcoming adrenal fatigue and its symptoms. For more information, contact Dr. Lam's team at +1 (626) 571-1234.

Mag Three has a calming, balancing effect on a body in stress

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“Climate Change Indicators: Heat-Related Deaths | US EPA.” US EPA, 1 Nov. 2023,

“Hot Weather and Your Heart.” British Heart Foundation,,to%20stay%20cool%20and%20hydrated.

Grudet, Cécile, et al. “Suicidal Patients Are Deficient in Vitamin D, Associated With a Pro-inflammatory Status in the Blood.” Psychoneuroendocrinology, vol. 210–219, 1 Dec. 2014,

“Stress Hormones Spike as the Temperature Rises.” ScienceDaily, 18 Apr. 2018,

Speakman, John R. “Obesity and Thermoregulation.” Handbook of Clinical Neurology, vol. 431–443, 1 Jan. 2018,

Dr. Lam’s Key Question

Yes, heat exhaustion can be serious for people with adrenal fatigue. This is because it promotes cortisol production that may impact already overworked and tired adrenal glands, making your condition worse.

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