Born to Sweat: The New Science of Heat, Health and Performance

By Chloe Wasserstrom 

Do you avoid heat? So did Bill Gifford, author and science journalist, for most of his life. That was until he came across a Finnish study that established the correlation between sauna bathing and longevity. The study suggests that the Finnish men who sauna bathed four to seven days a week had a lower risk of cardiovascular disease and all-cause mortality than the men who sauna bathed once a week.  

“I was not sold on going to sauna until 2022,” Gifford shares. “I started going to the sauna at my gym for the heck of it and felt better. I got addicted and looked at the study again and found there is a great longevity and athletic story here.” 

You may recognize Gifford from his co-authored bestselling book Outlive and his newest read Hotwired. Today, Gifford is not only passionate about getting uncomfortable in heat, but one of the most leading knowledgeable professionals in the field. He shared his expertise at the most recent Vail Health Learning Lab, sponsored by Pat and Tony McMunn, held in partnership with Vail Symposium, on the morning of July 9 at Vail Christian High School.  

Gifford first found Vail Health in 2023 while conducting research for Hotwired. “I found out about this cutting-edge research Vail Health was sponsoring (the CHILL’D Study). I thought it was amazing that a small local hospital in a mountain town was not only funding behavioral health programs but also funding innovative research.” Gifford then journeyed from Salt Lake City to the Vail Valley to participate in the CHILL’D Study almost exactly two years ago.  

While presenting for the Vail Health Learning Lab, Gifford showed pictures of his experience, and after making candid jokes about how uncomfortable he was under that much heat, he emphasized that on his drive back to Salt Lake, a drive he usually dreads, Gifford felt euphoric. He reaped the benefits of the heat.  

Gifford used science-backed research in a digestible way to synthesize why heat, when used safely and strategically, may be one of the most transformative ways to support long-lasting health.  

Delay Diseases

Gifford tells the story of an American man in his 70s who carried a specific genetic mutation that virtually guaranteed that he would develop Alzheimer’s disease by his mid-50s, like many of his relatives. Yet he had remained healthy — perhaps, doctors suspect, because he had high levels of heat shock proteins in his blood. These cellular proteins repair damaged proteins in the cell and clear out waste for optimal muscle and organ recovery. This man did not use a sauna, but he spent his days working in the engine rooms of Navy ships. The sauna is not the golden ticket to longevity, but elevating your body temperature might be. 

He then circles back to the Finnish study: the men who sauna bathed four to seven times a week had a 66% lower risk of Alzheimer’s or dementia. Spending time in heat, enough to make you sweat, benefits your circulation and is anti-inflammatory, repairing and cleansing your systems and delaying the onset of diseases.   

Athletic Performance

Athletes are using heat adaptation to enhance performance. Gifford, an avid cyclist, began riding his bike in the middle of the day, when sun and heat exposure peak. He shares that his first couple of sessions were highly uncomfortable, but then he adapted. 

“My muscles felt relaxed, and I felt relaxed when I used to feel panicked,” Gifford says. “It blew my mind the extent that someone like me could adapt to extreme conditions.” 

Spending time in heat, as long as it is not directly before bed, helps you sleep, and therefore adds to your recovery. 

He adds that there is emerging research suggesting that cold plunging immediately after sauna bathing or resistance training can blunt muscle growth. He suggests taking a few minutes after spending time in a sauna and before cold water immersion. 

Stay Social

There is something inherently collaborative about being in a sauna with others. A few years ago, Gifford traveled to Finland to experience traditional sauna culture first-hand. He discovered it was less about biohacking and more about spending time with community. It is also something the Finnish have been doing for over 2,000 years. It is a way of life.  

Going to the sauna means no phones and sharing space with people of all shapes, sizes and backgrounds. And in Finland, it also means being naked. Humans are collaborative and social beings, and spending time with others boosts our sense of purpose and well-being.  

Find Your Joy

There can be lot of comparative dialogue among health-conscious individuals. People compare their routines, meals and days to one another, striving for perfectionism. Not every person will get to the same body temperature, but that is not the point. Gifford encourages you to avoid perfectionism and strive for joy. 

How can you incorporate heat into your life, so it makes sense for you? There is no one-size-fits-all approach, because no one is the same. This may be hot tubbing, choosing to go for a run in the heat of the afternoon, hot yoga or anything that makes you sweat without feeling dizzy or sick. Choose a way to sweat that you look forward to, maybe even with friends, so you want to return while still listening to your body. 

“Sometimes you can learn something by leaning into something you think you don’t like and makes you uncomfortable,” Gifford says. “Leaning into it and making it a part of my life has changed and benefited me as an athlete and a person.” 

About the Vail Health Learning Lab

The Vail Health Learning Lab is a free community education series presented by Vail Health Foundation that brings leading experts to Eagle County to share evidence-based insights on behavioral health, physical health, and improving healthspan. Launched in August 2023 through the generous support of Pat and Tony and McMunn, the series helps community members make informed choices through engaging conversations grounded in the latest science. 

The inaugural Learning Lab featured Giulio Tononi, MD, PhD, and Charles (Chuck) Raison, MD, exploring innovative approaches to depression treatment. Since then, the Learning Lab has welcomed leading experts from across health care, science, and academia, including Ashley Mason, PhD; Tracy A. Balboni, MD, MPH, and Michael Balboni, PhD; Christof Koch, PhD; Christine Whelan, PhD; and most recently, bestselling author and science journalist Bill Gifford. A recording of Bill’s speech is available here.  

The series has explored a wide range of topics, including sleep and mental health, spirituality in health care, consciousness, purpose and well-being, and the emerging science of heat exposure, health, and human performance. Designed to make complex health and science topics accessible to the broader community, the series fosters curiosity, connection, and informed dialogue around the factors that influence resilience, longevity, and overall well-being.