On a hot day in spring 2021, as the Columbia College Koalas softball players in South Carolina left the field at the end of an inning, athletic trainer Kenya Moore noticed a disoriented player.

The player complained of dizziness, shortness of breath and muscle tremors. Suspecting possible heat stroke, Moore said she put her in an ice bath and called 911. As the player recovered and Moore examined the circumstances leading up to the incident, one thing stood out: The athlete had just switched her ADHD medication.

The incident stuck with her, and Moore, now a graduate teaching and research assistant in the athletic training program at the University of South Carolina, is among a group of sports medicine experts working to raise awareness about the elevated risk of heat stroke faced by athletes who take medications for conditions including ADHD, anxiety and depression. Experts are also calling for more research, especially as mental health awareness has prompted more people to seek help, which often includes medication.

Federal data show that heat illness diagnoses and heat stroke deaths have increased as global temperatures have risen. This summer, the hottest on record globally, five middle and high school football players in the U.S. died of heat stroke — the most since 2011, according to the National Center for Catastrophic Sport Injury Research.

“It’s almost like one of those perfect storm kind of things,” said Michael Szymanski, a research associate at the University of Connecticut. UConn is home to the Korey Stringer Institute, which studies heat-related deaths in sport.

Nearly one in three college students is on some type of psychotropic medication, according to the 2023-24 Healthy Minds Study of college students’ mental health. It is not uncommon for young adults to have multiple mental health conditions and to take more than one medication. About 35% of elite athletes “suffer from disordered eating, burnout, depression and/or anxiety,” according to a 2021 statement from the American College of Sports Medicine.

Nationally, doctors wrote 567 million prescriptions for mental health medications in 2022, according to data research company Statista, second only to prescriptions for drugs treating hypertension. That includes middle schoolers and middle-aged weekend warriors, who are less likely than college and pro athletes to be monitored by medical staff but could also be at higher risk for heat illness.

Studies show medications for treating mental health conditions can increase the risk for heat stroke by constricting blood vessels or inhibiting sweating, which prevents the body from adequately cooling itself. They can also raise blood pressure and core temperature, decrease the body’s perception of fatigue and/or put a general strain on the cardiovascular system.

“Blood vessels expand to let the heat dissipate during exertion,” Szymanski said. But stimulants, for example, can hamper that mechanism because they constrict blood vessels. “You just have a ramped-up system.”

In June, Dawn Emerson, clinical assistant professor at the University of South Carolina, spoke to the National Athletic Trainers Association about four types of mental health medications — antipsychotics, antidepressants, anxiolytics and stimulants — and their possible connection to heat stroke. She found that drugs with possible risk factors include popular brand names such as Adderall, Ritalin, Xanax and Ambien, as well as Bupropion, a generic antidepressant often sold under the brand name Wellbutrin.

Emerson was a researcher on a 2021 study that showed higher body temperatures among marching band participants on medications for mental health.

Erin Pettinger, an athletic trainer at Georgetown University who attended Emerson’s presentation, said the research rang true for her. She’s seen a rise in the number of athletes on these medications and counts about 40 on her current rosters. Several years ago, during a particularly hot fall in Washington, D.C., about six of her athletes suffered from heat illness over the span of a week.

“The common denominator of all these guys was that they had all been diagnosed with ADHD, and were all on medication,” she said.

Former University of Maryland football player Jordan McNair, who died of heat stroke in 2018, had been taking prescription Vyvanse, a stimulant used to treat ADHD. The independent investigation into his death determined that team medical staff should have identified the medication as a risk factor. “There is general concern among the medical community for student-athletes involved in physical activity while taking stimulant medication, though no precautions are generally listed on the drug information sheets,” the report stated.

When asked whether these types of drugs are tested for heat stroke risk or whether they list heat stroke as a possible risk factor, a spokeswoman with the U.S. Food and Drug Administration wrote that each drug’s approval process is unique and she couldn’t answer based on the four classes of drugs.

Last year, the FDA updated the warning information on stimulants used to treat ADHD, listing Adderall, Concerta, Dexedrine and Ritalin as examples. The updated labels tell patients to look out for increased heart rate or blood pressure but do not mention heat stroke, exercise or exertion.

ESPN did not find any mention of heat in a review of various FDA medication guides. Emerson said it was unlikely that any manufacturer is testing specifically for heat-related interactions.

“They discuss all the cardiac, renal and other types of effects but not specifically heat,” she said. “The issue is that if something affects those systems, then it affects thermoregulation.”

Sports medicine professionals face challenges in keeping track of athletes’ medications. Athletes might not want to disclose such information for fear of being stigmatized, and many athletes come to college or a new team using drugs prescribed by a hometown physician rather than a team or university doctor. A lesser-but-important factor is the perception by some athletes that certain mental health medications improve performance or act as appetite suppressants — reasons for taking them that athletes would not want to share with sports medicine staff.

Moore, the former Columbia College athletic trainer, said the softball player who suffered heat illness had been prescribed medication by a doctor not affiliated with the team or school.

“I know we had conversations around, ‘Hey, [do we] need to communicate again to the physician that this happened? You’re not feeling too well. Is there a way to alter the dose?'” she said.

At middle and high schools, which sometimes do not have athletic trainers, parents should make sure the school is aware of any medications and possible risk, said Tim Neal, director of athletic training education at Concordia University Ann Arbor.

Dr. Korin Hudson, sports medicine physician for MedStar Health in the Washington D.C. area, where she serves as team doctor for Georgetown University athletics and the Washington Wizards and Mystics, said she hopes athletes and athletic staff become more aware of the risks so that they can stay on their medication while finding other ways to deal with the heat.

“If someone has depression or anxiety, I don’t ever want to suggest that we’re going to have somebody not take their depression or anxiety medication,” Hudson said.

“I think that it’s probably better for us to educate athletes to not increase their risk further. Right? Don’t have three cappuccinos and have a bunch of caffeine right before your race or before the hot football day.”

In most cases, Pettinger said, the athletes prefer to stay on the medication and take greater precautions with hydration, sleep and other preventatives measures.

While much of the discussion focuses on heat stroke — of which 72 football players have died since 1996 — Neal said it’s worth monitoring the possible effects of medication simply because heat risks can inhibit how well athletes practice or compete.

“Because they’re tired or they’re dehydrated, not to the point where they need care, but it diminishes their performance,” he said. “And then when their performance diminishes, guess what that does? It makes them anxious or it gets them depressed.”

Hudson, who volunteers at the Boston Marathon, said the elevated risk for heat illness extends beyond athletes engaged in regular competition to people of all ages participating in races and other outdoor events, which prompts a greater need for awareness.

“When we think about the marathons and the mass events, we’re now looking at 40-year-olds and 50-year-olds who are on ADHD medications, too. So they’re still on their stimulants, as now they’re starting to take the blood pressure medications,” she said. “We just need to think about what that does for us in terms of event safety. I think awareness is number one.”