Your medications could be making you even more vulnerable to record-setting heat.
Breana Turner, 27, a doctoral candidate who takes the antidepressant venlafaxine to treat anxiety, was participating in a parade on a sweltering afternoon this June in Roanoke, Va., when her ears started ringing and her heart started racing. She vomited and was rushed inside.
Emergency medical technicians placed cool compresses on her lower back and neck. The EMTs reminded her that antidepressants can increase the chance of suffering heat-related illnesses.
Since starting the medication two years ago, Turner had adjusted to taking it after morning workouts, “so I don’t have such a visceral reaction to heating up.” The threat of overheating still caught her by surprise.
“This is a very common medication but a lot of people don’t realize that you have to take extra precaution,” Turner said.
Antidepressants are one of several classes of medications that can make people more vulnerable to heat by tampering with the body’s internal thermostat or interfering with its cooling strategies. Others include antipsychotics, diuretics, stimulants and heart medications such as beta blockers and ACE inhibitors.
The risk is growing during longer, more frequent heat waves: Last summer was the hottest on record , and this one is setting records, too . The rate of emergency-room visits for heat-related illnesses was higher last summer than in the previous five.
Venlafaxine belongs to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors that can cause excessive sweating.
The drugs, along with selective serotonin reuptake inhibitors, can affect the hypothalamus, the part of the brain that regulates core body temperature , said Patrick McDonnell , a professor of clinical pharmacy at Temple University.
Too few doctors tell patients their medications might put them at risk even during short periods in extreme heat, said Dr. Cheryl Holder , a leader of the Miami-Dade Climate and Heat Health Task Force.
“It’s not the same summer that you used to have,” she said. “You have to now change up your life.”
Heat exhaustion can look like dizziness, nausea, tiredness, sweating and cramps. People should hydrate and rest in cool places as soon as they feel these symptoms, Holder said. Otherwise the condition can quickly devolve into heatstroke, with symptoms including confusion, loss of consciousness, seizures and hyperthermia.
ACE inhibitors can decrease thirst, which can lead to dehydration, she said. Beta blockers, also used for heart diseases, can decrease blood flow to the skin. Drugs with anticholinergic properties—such as certain antihistamines, muscle relaxants and medications for overactive bladder—can impair the sweating response.
Many of these drugs are associated with an increased risk of heat-related hospitalizations, a study published in 2020 in the journal PLOS One found. But the extent to which these drugs pose risks isn’t well studied, said Dr. Soko Setoguchi , an epidemiologist at Rutgers University who co-wrote the study. Setoguchi said people should avoid heat, not their medication.
Leigha Standinger, 28, suffered heatstroke in 2020 during her first summer taking an antidepressant for anxiety.
She was with her husband and friends in the Thousand Islands region that stretches between Ontario and New York. They sat outside on a dock watching the sunset on an evening with a temperature in the low 90s.
When Standinger stood up, her vision blurred.
“Something’s wrong, something’s wrong,” she said. Her husband thought she was having a panic attack. She took a few steps and collapsed.
Standinger woke up on an ambulance stretcher. “I thought I had died,” she said.
In the emergency room, doctors diagnosed her with heatstroke , a life-threatening condition in which the body overheats to a temperature above 104°F. They said her antidepressant, Zoloft, could have made her more sensitive to the heat. It was her first time hearing of the risk.
“I probably would have taken more precautions, but I was never aware of that,” she said.
Standinger, who hikes and runs half-marathons near her home in Rochester, N.Y., has adapted to the risk. She takes salt tablets when running to mitigate the risks of sweating out important nutrients. She starts and ends the day with electrolytes, whether it is hot or cold outside.
Hydrating helps her avoid heat-related health problems, though drinking too much water can put people’s health at risk too.
“It kind of sneaks up on you still, even if I’m careful,” she said.
