Huberman Lab

Dr. Craig Heller on Huberman Lab: How Palm Cooling Works

Glabrous skin on the palms, soles, and upper face dissipates heat through AVAs; cooling these spots between sets extends reps and delays muscular fatigue.

AHAndrew HubermanhostCHCraig Hellerguest

Aug 7, 2025·31m·Watch on YouTube ↗

📖 CHAPTERS

1. 1
   0:00 – 3:30

   Cold Showers, Ice Baths, and the Real ‘Benefit’ of Cold

   Huberman introduces Dr. Craig Heller and raises the popular interest in cold showers and ice baths. Heller explains that while these induce a strong adrenaline-driven shock, the perceived benefits often do not translate into meaningful improvements in physiology or performance and can sometimes hinder heat loss via vasoconstriction.

2. 2
   3:30 – 6:50

   Heat Portals: Palms, Soles, and Upper Face Explained

   Heller introduces ‘glabrous’ skin—hairless regions such as palms, soles, and upper face—as special heat-exchange portals. He describes the underlying arterio-venous shunts that allow high-volume blood flow for rapid heat transfer and contrasts these with normal capillary-based skin.

3. 3
   6:50 – 9:50

   Aerobic vs Anaerobic Exercise: How Heat Limits Performance

   The discussion shifts to how heat buildup limits both endurance and strength. For aerobic efforts, pre-cooling increases the body’s capacity to absorb heat, improving time to fatigue. For anaerobic work, localized muscle heating rapidly impairs enzyme function and ATP production, triggering sudden muscular failure.

4. 4
   9:50 – 16:00

   Why Local Cooling (Thighs, Neck, Ice Water) Often Fails

   Huberman explores why simply cooling hot muscles, drinking ice water, or using neck/head ice packs doesn’t reliably fix performance-limiting heat. Heller explains that muscles are insulated, heat leaves primarily via blood, and cooling certain areas can mislead the brain’s thermostat, cause vasoconstriction, and actually slow true core cooling.

5. 5
   16:00 – 20:30

   Hyperthermia Risks and Misleading Sensations of Coolness

   They examine the dangers of hyperthermia and why it’s tricky to self-diagnose. Heller notes that as individuals approach heat stroke, they may stop sweating and vasoconstrict, feel terrible yet keep pushing due to motivation, and that subjectively feeling better from local cooling doesn’t guarantee safe core temperatures.

6. 6
   20:30 – 33:00

   Glabrous Portals in Mammals and Practical Implications (Hands, Feet, Face)

   Heller connects human heat portals to mammalian evolution, explaining that fur-covered animals evolved specialized non-furred regions (pads, ears, faces) for heat loss. They translate this into practical advice: don’t over-grip handlebars, avoid thick gloves and socks when possible, and understand why pouring water on the head can selectively cool the brain.

7. 7
   33:00 – 37:00

   Palmar Cooling Breakthrough: The Greg Clark Dips Experiment

   They recount a pivotal case study with NFL tight end Greg Clark that demonstrated how palmar cooling can massively boost work volume in strength training. By cooling his palms between sets of dips using a specialized device, Clark first doubled and then eventually tripled his total dip count over several weeks.

8. 8
   37:00 – 40:00

   Endurance in Extreme Heat and Why Palms/Soles/Face Beat Armpits/Groin

   The conversation moves to endurance studies with treadmill walking in hot environments. Continuous cooling of palms, soles, and face dramatically outperforms standard medical field protocols (cold packs in armpits, groin, neck) for lowering core temperature and extending endurance.

9. 9
   40:00 – 43:00

   Coolmitt Technology: Optimal Temperature, Timing, and Why Ice Water Fails

   They discuss the specific device developed from Heller’s work (Coolmitt by Arteria) and why its design choices matter. The mitt provides cool—not ice-cold—convective cooling to the palms, exploiting the steep part of the heat-loss curve in short intervals while avoiding vasoconstriction.

10. 10
    43:00 – 45:00

    DIY Palmar Cooling and Ensuring You Don’t Close the Portals

    Huberman asks for practical at-home strategies while Coolmitt expands availability. Heller offers a simple test—whether your hands feel warm or cold after holding a frozen pack—to see if you’ve preserved or shut down blood flow, and explains limitations of static packs under feet or on the face compared with moving cooling mediums.

11. 11
    45:00

    Lasting Adaptations: Keeping Gains After Cooling and Final Advice

    In closing, Heller confirms that adaptations made under enhanced work volume with cooling are durable: increased strength and muscle size remain even when cooling is no longer used. Huberman encourages listeners to apply the principles with whatever tools they have and thanks Heller for translating rigorous lab science into actionable protocols.