Sweating. Shivering. Why do we do it?

It’s thermoregulation, of course.

Thermoregulation is the biological mechanism responsible for maintaining a steady internal body temperature. If your body can’t do that, it can overheat, leading to hyperthermia, a condition that can be life threatening.

According to Tina George, MD, a family medicine physician with LVPG Family and Internal Medicine–Meade Street, Dunmore, there are many prescription and over-the-counter medications that can affect the human body’s ability to manage high temperatures.

Here are common medication categories and what can result when the mercury rises.

Blood pressure medications

“Since ACE inhibitors work by keeping our blood vessels from narrowing, they reduce our ability to sweat,” Dr. George says. “If we can’t sweat, we can’t cool down. These drugs also lower blood pressure, so in high temperatures, they can make us more prone to fainting.”

Beta blockers, which treat heart and circulatory problems, can act similarly.

Examples: lisinopril, losartan, metoprolol

Diuretics (water pills)

These medicines reduce fluid buildup in the body by helping the kidneys remove salt and water through the urine.

“While this lowers the amount of fluid flowing through the veins and arteries, it increases urine production, leading to fluid loss and possible dehydration,” says Dr. George.

In this case, she says, it’s important to replace the electrolytes (sodium, potassium and magnesium) that are lost.

Examples: Lasix (furosemide), metolazone

Psychotropics

Both antidepressants and antipsychotics fall into this category, and the effects in the heat are a mixed bag. Some increase sweating, while others impede sweat production. Some can lower blood pressure and others can affect brain function.

“In these two categories of drugs, we have an interference with thermoregulation and a reduction in thirst,” says Dr. George. “The effects can be varied on top of just feeling hotter and more uncomfortable.”

Examples: Prozac (fluoxetine), Lexapro (escitalopram), Haldol (haloperidol), clozapine

Anticholinergics

This class of drugs is used to treat a variety of conditions including chronic obstructive pulmonary disease (COPD), incontinence, motion sickness and asthma among others. They essentially block the signals regulating certain body functions and can reduce sweating, causing your body temperature to rise.

“During hot weather, this can make it harder to adapt to the heat,” says Dr. George.

Examples: scopolamine (scopolamine transdermal), Robitussin Multi-Symptom (acetaminophen, diphenhydramine, phenylephrine), Dramamine (dimenhydrinate)

Other concerns

When using topical medications for conditions such as high blood pressure, chronic pain or cancer, individuals should be cautious.

“Heat will affect the rate of absorption with these drugs, potentially giving the person a higher level of medicine than what was prescribed,” says Dr. George.

Certain medications can also cause the skin to be super sensitive to sunlight and UV light.

In all these situations, be certain you are aware of the risks and take measures to protect yourself like staying hydrated, seeking out shade and frequenting air-conditioned spaces.

It’s more than likely that the medications you’re taking are necessary for treating a condition.

Experts say you should not stop taking them. Always consult your physician.

To make an appointment with a primary care physician call 888-402-LVHN (5846) or log onto LVHN.org