Feeling overheated under the hot summer sun is a common experience. But for some people, experiencing a spike in body temperature—known as hyperthermia—can result from taking certain medications. A recent medical journal article discussed a case of a person whose body temperature reached 104 degrees Fahrenheit while on multiple medications. Fortunately, this patient recovered but other patients that develop a temperature of 104 or greater often do poorly.

In the U.S., heatstroke claims the lives of hundreds of people every year. Adults ages 50 and older make up 80% of the fatalities. Hospitalizations due to heat-related illness occur mostly in the Midwestern and Southern states, where summer temperatures are the highest.

Nearly 30 years ago, Chicago was devastated by the 1995 heatwave when over 700 people died in the metropolitan area in just a few days. A lot has changed since then, including an increase in our planet’s temperature. Information from the National Oceanic and Atmospheric Administration from the past 30 years shows that summer temperatures in Chicago are hotter by 2 degrees Fahrenheit, likely due to climate change. As a result, the risk of suffering heat-related injuries, such as heatstroke, including those exacerbated by medications is expected to increase. 

People who are most susceptible to heatstroke include:

• Infants
• Elderly
• Athletes (e.g., football players in full gear at camp)
• People who work outside and physically exert themselves under the sun
• Individuals taking certain medications that make them vulnerable to dehydration

Symptoms of heatstroke include:

• High body temperature
• The absence of sweating, with hot red or flushed dry skin
• Rapid pulse
• Difficulty breathing
• Strange behavior
• Hallucinations
• Confusion
• Agitation
• Disorientation
• Seizure
• Coma

What can you do to prevent heat-related complications due to certain medications? The most important step is to familiarize yourself with all your medications and the risks associated with them. Discuss with your primary care physician or pharmacist the major adverse reaction associated with each medication and if it could impair body temperature regulation in hot weather. 

Medications that can impair the body’s ability to respond to external heat and cool off include:

• Antihistamines and anticholinergic drugs, such as those in sinus, allergy, and cough and cold preparations, can reduce the body’s ability to sweat. This impairs heat dissipation and can increase the possibility of heat stroke.
• Antipsychotic medications can impair the body’s ability to regulate its internal temperature through their effects on the thermoregulatory center in the hypothalamus, which is in the brain. Some antipsychotic and antidepressant medications also have anticholinergic properties, which can make heat stroke more likely.
• Certain cardiac medications like beta blockers and calcium channel blockers decrease the shunting—or movement—of blood to the skin, so the ability to release heat is impaired. Diuretics cause increased fluid loss and dehydration.
• Stimulant medication and drugs such as ephedrine, amphetamines or cocaine increase metabolism and increase internal body temperature. They also can constrict blood vessels, which then decreases the amount of heat that can be released through the skin.

Preventing heatstroke is easy once you’re aware that it can happen and know the steps to take. Here’s how to keep your body temperature from rising too high in hot weather:

• When working or playing sports outside, take frequent breaks in cooler, shaded areas.
• Avoid becoming dehydrated. Drink plenty of fluids, even if you’re not thirsty.
• Avoid caffeinated or alcoholic beverages, which will increase water excretion through the kidneys and can lead to dehydration.
• Wear cool, light-colored clothing.
• Air-conditioning is the best way to avoid heat stroke during hot summer spells. If you do not have access to air-conditioning, know where public/community cooling centers are located, such as indoor shopping malls, libraries and other public places.

To help others avoid heatstroke, check on those who may be isolated and/or at risk for heat related illness, such as people who are elderly, overweight/obese or mentally ill.

If we all follow these steps, we can avoid a repeat of the heat disaster of 1995.

Be well, Tony