Heat Stroke and Related Heat Illnesses — How To Keep Your ‘Cool’ During Heat Waves

Joseph R. Anticaglia MD
Medical Advisory Board

The National Weather Service reported that the average temperature for the month of June 2021 in the US was the hottest on record. “An Inconvenient Truth” is that climate change is real and its damaging medical and economic effects are real and intensifying.

In June and July of 2021, the Pacific Northwest and Southwest were in the throes of a heat inferno that set-in motion a spike in heat-related emergency department visits and the cause of hundreds of deaths. Record triple digit temperatures were recorded from Phoenix Arizona to Portland Oregan to Seattle Washington, and in British Columbia, a stifling 118.2 F on June 28, 2021.

The temperature in Death Valley, California on July 7 of this year soared to a blistering 130 degrees F, one degree less than the current world record recorded at Kebili, Tunisia on July 7, 1931. Because of the recent heat waves, renewed interest, and examination of heat-related illnesses have been on the front burner.

How Do We Keep Your Cool?

Your body sweats to prevent heat illnesses. The hypothalamus is a structure in the central region of the brain that helps to control body temperature. When the temperature becomes elevated and the body becomes overheated, the hypothalamus excites sweat glands to secrete sweat onto the surface of the skin to restore temperature balance.

However, the hypothalamus can become overmatched if certain factors are present such as exceedingly high external temperatures coupled with high humidity. Additionally, certain medications, or medical conditions or strenuous physical activities in hot, humid weather can overly tax the body. In these scenarios, the ‘core- internal’ body temperature can become dangerously elevated leading to heat related illnesses.

People at greatest risk for heat-related illness include infants and children, adults 65 years of age and older, individuals who are overweight, and people, as noted, who have chronic medical conditions or on certain medications. Furthermore, construction workers, farm laborers and those engaged in physical activities be it athletic or otherwise during heat waves put themselves at risk for heat illnesses.

Four Heat -Related Illnesses

Heat-related illnesses are caused by high environmental temperatures and humidity that give rise to extreme core temperatures. They can be mild as in heat rash or deadly as in heat stroke.

  • Heat rash develops during hot, humid weather when blocked pores (sweat ducts) trap sweat under your skin. Areas of redness, red bumps or blisters on the skin can be very itchy. It’s also known as prickly heat and miliaria and is not just for babies.
  • Heat cramps are painful muscle spasms that usually occur during or after strenuous exercise in hot weather. The cramps can involve the abdomen, legs, or arms. Most often the cramps are due to salt depletion (dilutional hyponatremia — sweat losses are replaced solely with water). The core temperature is normal, the skin is moist and cool, and muscle twitching may be present.
  • Heat Exhaustion results from strenuous physical activity for long hours while being exposed to feverish temperatures. It causes heavy sweating often associated with inadequate fluid and salt intake. It results in dehydration, a fast and weak pulse and rapid breading.
  • Heat Stroke (“Sunstroke”) is a life-threatening emergency characterized by a sudden loss of consciousness and failure of the body’s heat-regulating system. It happens within minutes when a person’s temperature rises above 106 degrees F (41degrees C) and the skin is hot, red, and dry. Call 911 if a person is exposed to intense heat and is not sweating, feels nauseated, complains of dizziness, or is confused.

One Too Many — Mr. Perez

The hot weather did not prevent millions of Americans from enjoying the 4th of July weekend. A friend of mine put it this way: “It was great to have family and friends over for the cookout., like old times — grilled hamburgers, hot dogs, and chicken. We had plenty of potato salad, corn on the cob, green salad with tomatoes, cucumbers, and of course watermelon.” But not everyone was celebrating.

A few days later I read that a farm worker, 38 y/o Sebastian Francisco Perez, died of heat stroke while laboring outside of Portland, Oregan in 115 degrees heat. He and his fellow workers supplied lots of the food we ate on July 4th, as well as a good portion of the food we eat every day. His death is another example of “one too many” preventable deaths.


  • Stay hydrated with adequate fluid and salt intake, preferably, electrolyte fluids
  • Outside workers should increase activities gradually until acclimatized.
  • Coaches, athletes, and parents must be educated about heat-related illnesses, and prevention.
  • Avoid unnecessary exposure to heat during heat advisory warnings.
  • Wear loose fitting, light colored, light weight clothing that is permeable to moisture
  • Avoid sugary, caffeinated, and alcoholic drinks
  • Public education campaign to increase awareness and prevention of heat-related illnesses.
  • Stay cool in an air-conditioned area

Heat — related illnesses are underestimated and undertreated emergencies. Heat Stroke that causes brain dysfunction or death is preventable. Best outcomes involve early recognition of the problem and rapid initiation of cooling. Any cooling method is the best choice if it is done rapidly without harming the person.

Delays in cooling heat stroke sufferers or in calling 911 for assistance increase the likelihood of complications and death. One death due to heat stroke, be it in aa overheated car or at a worksite, is “one too many.”


Heat Wave is five or more consecutive days during which the daily maximum temperature surpasses the average maximum temperature by 9 degrees F (5 degrees C).

Heat Dome happens when the atmosphere traps the hot ocean air over areas like a lid or cap creating sweltering heat.

Temperature Balance
Metabolic reactions in the body continually produce heat. Conversely. the body is continually losing heat to the surroundings. When the one equals the other, the body is in temperature balance. However, external factors can disrupt this equilibrium.


  1. Jacqueline A. Nemer; Marianne A. Juarez; Disorders Related to Environmental Emergencies; Current Medical Diagnosis and Treatment, 2018
  2. CDC FAQ Natural Disasters and Severe Weather
  3. CDC Warning Signs and Symptoms of Heat-Related Illnesses
  4. Al Gore; An Inconvenient Truth — May 24, 2006 Documentary

✓ Addendum CDC Heat Related Illnesses

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.