This episode is brought to you by Rupa Health, Cozy Earth, BiOptimizers, and InsideTracker. Cold-water immersion and heat therapy are among the biggest wellness trends of the past few years, but they have a long-standing tradition of being practiced around the world. Today, I’m excited to sit down with Dr. Susanna Søberg to discuss the benefits of cold and heat therapy and how they have the potential to activate our longevity pathways.  Dr. Susanna Søberg is a Ph.D. in metabolism and specializes in functional breathing and cold and heat exposure for health optimization. She is the Founder and CEO of The Soeberg Institute, where she teaches how to "stress up to stress down" using natural stressors. Her scientific discoveries have shown the minimum threshold for how much cold and heat we need to reap the health benefits. She is an international author of Winter Swimming, a number-one bestseller on Amazon. Her book has been translated into 13 languages. This episode is brought to you by Rupa Health, Cozy Earth, BiOptimizers, and InsideTracker. Rupa Health is a place where Functional Medicine practitioners can access more than 2,000 specialty lab tests from over 35 labs. Check out a free, live demo with a Q&A or create an account at RupaHealth.com. Get 40% off your Cozy Earth sheets at cozyearth.com. Use the code MARK40. BiOptimizers is offering my listeners 10% off Sleep Breakthrough. If you buy two or more you’ll get a free bottle of Magnesium Breakthrough. This is a limited-time offer. Go to sleepbreakthrough.com/hyman. Use the code hyman10.  InsideTracker is offering my community 20% off at insidetracker.com/drhyman. Here are more details from our interview (audio version / Apple Subscriber version): How hot and cold therapy increases health and longevity (5:08 / 3:19)  The physiological effects of cold therapy (11:05 / 8:37)  The cognitive and mental health benefits of cold therapy (20:40 / 18:40)  How cold therapy activates brown fat (31:06 / 26:50) Cold therapy for pain reduction (37:48 / 33:33)  Cold therapy best practices (41:54 / 37:40)  Is hot and cold therapy better in tandem? (1:00:49 / 53:30)  The physiological effects of hot therapy (1:03:57 / 56:42)  How much time should you spend in the sauna? (1:13:30 / 1:09:17)  Benefits of infrared saunas and hot baths (1:16:58 / 1:12)  Research mentioned in this episode Get a copy of Susanna’s book, Winter Swimming: The Nordic Way Towards a Healthier and Happier Life. Get a 10% discount on her three-week online Thermalist course with code HYMAN at https://www.soeberginstitute.com/course/live-thermalist. Learn more about your ad choices. Visit megaphone.fm/adchoices