The saying goes that you should stay out of the kitchen if you can’t take the heat, but new research suggests otherwise — for the sake of your blood pressure.
In a study published in the Journal of Applied Physiology, researchers at UNT Health Fort Worth found at-home heat therapy may hold the key to lowering blood pressure. A group of older adults wore heated pants for an hour a day, four days a week. After eight weeks, their blood flow improved and their systolic blood pressure, which measures blood flow when the heart beats, dropped by around 5 points.
The study comes at a time when nearly 120 million American adults have high blood pressure, but only one in four of those adults has it under control. In Texas, about 32% of adults report being told by a health care professional they have high blood pressure. And in 2023, high blood pressure was a primary or contributing cause in over 664,000 deaths in the United States, according to the Centers for Disease Control and Prevention.
Exploring ways to reduce the risks of high blood pressure — like stroke and heart attack — is crucial, and “this is an important proof-of-concept study,” said Dr. Amit Khera, a cardiologist and professor of medicine at UT Southwestern Medical Center, who was not involved in the research.
Khera doesn’t see heat therapy “as a replacement for blood pressure medicine,” he said, but he does find it intriguing. “It could be a potential adjunctive treatment for other heart diseases and problems.”
Crank up the heat
Anyone who’s stepped out of a sauna or settled into a hot tub knows heat can feel good. Research backs that up: A 2025 study found soaking in hot water can lower blood pressure, stimulate the immune system and, over time, improve how the body handles heat stress.
Other studies similarly found heat therapy can improve cardiovascular function in middle-aged and older adults — whether or not they have chronic diseases — and that its benefits can be comparable to aerobic exercise, said Scott Romero, an associate professor of physiology and anatomy at UNT Health, who led the study.
“The crazy thing is, the cardiovascular responses to heat exposure are almost identical to exercise,” Romero said. “Heart rate changes, blood flow changes, muscle changes. It’s almost identical, which is one of the reasons why we think that heat therapy is efficacious, especially in a clinical population, because it almost mimics exercise.”
Raising your core temperature with heat therapy usually means regular time in a sauna or hot tub — tough if you don’t have either. To make heat therapy more accessible, Romero and Ysabella Ruiz, the study’s first author and a graduate student in Romero’s lab, tested whether pants lined with tubes that circulate hot water could deliver similar cardiovascular benefits. (The pants, Romero said, were adapted from suits developed by NASA to study cardiovascular function during heat stress.)
The researchers recruited 19 adults, aged 55 to 80, without a diagnosed condition of high blood pressure and split them into two similarly aged groups. One wore heated pants circulating water at nearly 124 degrees Fahrenheit, which raised skin temperature to about 104 degrees. (Romero and Ruiz chose that setting based on earlier work showing it nudged up core body temperature by about one to two degrees Fahrenheit over an hour in older adults.) The other group wore pants that were mildly warm, with the water heated near 88 degrees Fahrenheit and skin temperatures just over 90 degrees. Romero said these pants would feel pleasant but wouldn’t make people sweat like in the heat therapy group.
Participants had their blood pressure checked three ways: at the start of the study, during the day while active and after eight weeks. The researchers also used ultrasound before and after the treatment to see how well it helps widen the endothelium, or inner lining, of a blood vessel to let blood flow. Problems with this lining are among the earliest signs of aging in the circulatory system and can appear even without the usual risk factors for heart disease. When the lining stops functioning normally, the risk of clogged arteries, cardiovascular disease and complications such as stroke or death goes up.
The participants kept their normal routines, setting aside an hour a day, four days a week, to wear the pants. After eight weeks, when they returned to the lab for final tests, the results stood out: systolic blood pressure was about 5 points lower for the heat therapy group, and on ultrasound, the inner lining of the blood vessels among those group members seemed much improved, dilating better than before.
Further studies needed
Romero and Ruiz aren’t sure why the heated pants led to these results. One possibility, Romero said, is that the brain adjusts how tense or springy blood vessels are in response to heat. Another is that the vessels change and improve with repeated heat exposure.
“We think that some of those things are actually changing long term,” Romero said. “We didn’t actually measure the mechanisms,” since the study focused on whether the therapy would be effective in this population.
Khera is curious how the results would translate to people with diagnosed hypertension. There’s also a question of the clinical significance of a modest drop in blood pressure when treating patients one on one.
“On a population level, if you treated 100,000 people, 5 points help,” Khera said. “But on an individual level, [blood pressure] pills are much stronger than that. … If your blood pressure is modestly high and you want to start with this as a feasible first step, as they continue to do more studies, this could be a potential treatment.”
Khera added it’s unclear how long the benefits of heat therapy last. Romero and Ruiz acknowledged that’s something they hope to determine as they investigate the underlying biology behind the results.
The researchers’ longer-term goal with at-home heat therapy is to create an accessible way for older adults to acclimate to heat.
“We know that older folks are most at risk for heat-related illnesses, especially in Texas, where we have really hot summers,” Romero said. “Those older folks are the ones who are getting sick and the ones that are dying during heat waves. Our idea is to be proactive about these heat waves and have individuals heat acclimate themselves at home.”
Romero said preliminary data from his lab suggests that at-home heat therapy can help older adults build better resilience to heat stress. That matters because heat-related deaths disproportionately affect older adults, and research from 2024 projects that as many as 246 million more people in this demographic will face dangerous levels of heat by 2050.
Miriam Fauzia is a science reporting fellow at The Dallas Morning News. Her fellowship is supported by the University of Texas at Dallas. The News makes all editorial decisions.