When Should I Worry About...

Medications That Don't Mix Well With the Sun or Heat

June 3, 2024 - Katie McCallum

Surviving the sweltering summer months is tough for us all, but it can be particularly challenging if you're on medication that makes you more vulnerable to heat or sunlight.

Perhaps surprisingly, several common medications — including certain pain relievers, weight loss drugs and ADHD medications — can cause heat intolerance and sun sensitivity.

"Some medications impair the body's ability to regulate its temperature, increasing the risk of heat exhaustion and heat stroke," explains Dr. Nish Shah, a primary care sports medicine doctor at Houston Methodist, "Others make the skin more sensitive to sunlight, called photosensitivity, which can lead to an increased risk of not just sunburn but skin damage."

Staying informed about your medications and how they affect your heat and sun sensitivity can help you enjoy the summer safely.

Medications that increase heat sensitivity

Medications might not be top of mind on a hot, humid day, but it's essential to know if what you're taking makes you more vulnerable. The list of medications that cause heat intolerance may be taken for everything from high blood pressure and weight loss to anxiety and depression.

Medications that increase sensitivity to the heat include:

  • Diuretics – increase urine production, leading to fluid loss, decreased sweat production and potentially dehydration
  • Anticholinergics – block the neurotransmitters that signal sweat glands, reducing sweat production
  • Beta blockers – slow heart rate, limiting the body's ability to circulate blood efficiently for cooling
  • Stimulants – increase metabolic rate, which can impair the body's cooling mechanisms
  • Antidepressants – can affect the hypothalamus, which regulates body temperature, and can impair sweating


(Related: How Sweat Cools You Down)

"Diuretics and beta blockers may be used to treat high blood pressure, anticholinergics to help manage various conditions like bladder issues and COPD and stimulants may be used for ADHD and weight loss," explains Dr. Shah. "Beta blockers are also used to treat heart conditions, such as coronary artery disease, arrhythmia and heart failure, and certain SSRIs and SNRIs are used as antidepressants."

Medications that cause sun sensitivity

Overheating isn't the only concern. Some medications can also make your skin more sensitive to the sun, increasing the risk of sunburn and cancer-causing skin damage.

The list of sun sensitive medications includes:

  • Antibiotics – drugs like doxycycline, ciprofloxacin and sulfonamides can interact with UV light to create compounds that damage skin cells
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) – ibuprofen and naprozen can cause phototoxic reactions when the skin is exposed to sunlight
  • Diuretics, particularly thiazides – increases the risk of photosensitivity
  • Retinoids – thins the outer layer of the skin, reducing its natural UV protection
  • Antidepressants – certain tricyclics lead to increased sensitivty to UV light


Consult your doctor about medication side effects

It's important to understand the heat intolerance risks associated with anything you're taking, but you should never skip or discontinue taking a medication prescribed by your doctor without first consulting them.

"The key is to be aware," says Dr. Shah. "Know the potential side effects of the medications you are taking and don't hesitate to ask your healthcare provider questions about staying safe in the heat or sun. Never discontinue a medication without speaking to your doctor."

He adds that it's always important to have a heat-related emergency plan, especially if you're at higher risk due to a medication you're taking.

Tips for staying safe in the heat if you take one of these medications

If you take any of the medications mentioned, it's important to know how to protect yourself on a hot, sunny day. Here are Dr. Shah's tips:

  • Stay hydrated: Drink plenty of water, especially if you're taking diuretics
  • Seek shade or cool areas: Stay in shaded or air-conditioned spaces and avoid strenuous outdoor exercise during the hottest parts of the day
  • Wear appropriate clothing: Choose lightweight, light-colored, loose-fitting clothing to encourage evaporation of sweat
  • Apply sunscreen: Use broad-spectrum sunscreen with an SPF of 30 or higher any time you are outdoors, especially if taking a sun-sensitive medication
  • Recognize heat-related symptoms: Be aware of heat exhaustion and heat stroke symptoms, like dizziness, confusion and excessive sweating


Don't hesitate to seek medical attention when necessary.

"The high body temperature associated with heat stroke can damage your brain, heart, kidneys, muscles and other organs," warns Dr. Shah. "The longer heat stroke is left untreated, the more damage can be done to these vital organs — increasing the risk of long-term complications and even death."

What to do in case of heat stroke

Heat stroke is a medical emergency. If you or someone you love is showing signs of heat stroke, call 911 immediately. While waiting for help to arrive, try to cool the person down by:

  • Moving them into the shade or air conditioning
  • Loosening or removing clothing
  • Applying ice packs or wet towels to armpits and groin
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