David Beckham. Gordon Ramsay. Gwyneth Paltrow. Justin Bieber. These days, everywhere you turn, you hear celebrities touting the health benefits of sauna. Medical professionals are as well – including Peter Attia, a physician and author of the New York Times bestselling book Outlive: The Science and Art of Longevity.

When it comes to sauna and increased longevity, Dr. Attia says, “The burden of evidence is so strong, it’s becoming hard to ignore. … When you look at the largest published series on this, you see a benefit in all-cause mortality – a relative risk reduction of 40 per cent and an absolute risk reduction of 18 per cent. Those are ridiculous numbers."