We discovered the potential of alternating between hot and cold long before we knew the term “contrast therapy.” What struck us early on was how different we felt afterward. We would enter the spa feeling tired, stressed or jet-lagged and emerge feeling noticeably better. Later, when our careers moved closer to health and fitness, we learned why: A cold plunge releases a rush of endorphins in your brain. But contrast therapy also has long-term effects—longitudinal research from Finland shows that frequent sauna use is linked to increased longevity, and lower rates of cardiovascular and neurodegenerative disease.

If you’re trying contrast therapy for the first time, we suggest starting in the sauna and staying only as long as you still feel good. Don’t push past that point. When you come out, begin with a cool shower rather than going straight into the cold plunge. The body will adapt and become more comfortable with the cold over time, but too much too soon can be overwhelming. With the cold, breathing makes all the difference: Focus on slow exhales. It helps you stay calm and shifts your attention away from the discomfort.

For heat, most of the research points to 180° to 195°F for about 15 to 20 minutes, several times per week. The cold is less prescriptive, but anything under 60°F counts as cold exposure—we look for the moment the body begins to shiver as a sign that it has done its job.

The sauna tradition in Finland—where there are 3 million saunas for 5.5 million people—is unfussy, communal and approachable, and that’s the spirit we try to bring to Lore. It’s a shared space but also a personal one. Talk quietly, rinse before the pool, be mindful. And don’t obsess too much over degrees or minutes. If it feels good, keep going.