In this episode, my guest is Susanna Søberg, PhD. She earned her doctoral degree at the University of Copenhagen in Denmark, researching the effects of deliberate cold and deliberate heat exposure on metabolism and other aspects of human physiology. We discuss how cold or sauna can improve metabolism, cardiovascular and brain health, balance hormones, and decrease inflammation. Dr. Søberg discusses how deliberate cold protocols can improve glucose metabolism and insulin sensitivity and trigger release of neurotransmitters like dopamine and norepinephrine which enhance energy, mood, and focus. We compare cold showers and cold immersion, traditional and infrared saunas, and other variables. This episode provides actionable tools and answers to common questions about the use of deliberate cold and heat to improve health. For the full show notes, visit hubermanlab.com. Thank you to our sponsors AG1 (Athletic Greens): https://athleticgreens.com/huberman Plunge: https://plunge.com/huberman Maui Nui: https://mauinuivenison.com/huberman Thesis: https://takethesis.com/huberman InsideTracker: https://insidetracker.com/huberman Momentous: https://www.livemomentous.com/huberman The Brain Body Contract Tickets: https://hubermanlab.com/tour Presale code: HUBERMAN Timestamps (00:00:00) Dr. Susanna Søberg (00:03:23) Sponsors: Plunge, Maui Nui, Thesis (00:06:49) The Brain-Body Contract (00:07:40) Physiology in Uncomfortably Cold Environments (00:12:05) Tool: Water Temperature, “Cold Shock” & Discomfort (00:17:37) Cold Showers vs. Immersion in Water, Brown Fat (00:22:11) Cold Receptors, Brown Fat & Temperature Homeostasis (00:25:22) Shiver, “After Drop”, Healthy Stress (00:31:08) Long-Term Health Benefits of Deliberate Cold Exposure (00:35:48) Sponsor: AG1 (Athletic Greens) (00:37:02) Blood Pressure & Heath (00:38:26) Brown Fat, Insulin Sensitivity & Metabolism (00:45:07) Temperature Regulation, Brown Fat vs. White Fat (00:52:26) Cold Resilience, Scandinavia (00:59:07) Sponsor: InsideTracker (01:00:16) Winter Swimmers & Brown Fat; Discomfort (01:10:28) Sex differences & Brown Fat, Cold-Adapted (01:15:21) Diving Reflex & Parasympathetic Activation (01:18:44) Tool: Deliberate Cold & Sauna Protocol (01:23:11) Winter Swimmers, Shiver; Circadian Rhythm & Brown Fat (01:31:14) Tool: Minimum Threshold for Cold & Heat; Sauna & Cardiovascular Health (01:35:19) Tool: Maintaining Stimulus when Cold-Adapted; Shorter Sessions (01:38:09) Cold Exposure, Sleep Quality, Clothing (01:47:37) “Brown Fat Negative” & Shiver (01:52:13) Cold & Heat, Inflammation Reduction (01:55:40) Tool: “Soberg Principle”: End on Cold, Metabolism (01:59:39) Cold Exposure: Fed or Fasted? (02:00:32) Raynaud’s Syndrome; Hand/Feet Protection in Cold (02:05:21) Tool: Headache & Cold Exposure; Head Submersion & Head Coverings (02:11:29) Children & Hypothermia Risk (02:17:16) Gender Differences & Cold Exposure (02:19:57) Tool: Brief, Repeated Temperature Changes; Circadian Rhythm & Temperature (2:27:53) Zero-Cost Support, YouTube Feedback, Spotify & Apple Reviews, Sponsors, Momentous, Social Media, Neural Network Newsletter Title Card Photo Credit: Mike Blabac Disclaimer