A List of Palm Cooling Research
Palm cooling has been studied for decades with research spanning physiology, sports science, and military and occupational health. This post pulls together studies in one place, organized by what the study was actually measuring: heat stress mitigation, aerobic capacity, resistance training, and sport-specific performance.
The techniques behind the research
The studies below did not all cool the palm the same way. Across the literature, a few distinct methods show up:
- Subatmospheric pressure plus a heat sink. A sealed device applies a slight vacuum to draw blood into the hand while a cool surface extracts heat from it. This is the method behind much of the foundational Stanford work.
- Conductive Cool-not-Cold contact. The palm rests against a cool surface, gel pack, or cooling glove and heat transfers by direct contact. This is closest to how palm cooling is used in the field today.
- Cold-water immersion. The hands, forearms, or feet are submerged in cool water. Common in the military and occupational studies, where the goal is often rapid core cooling rather than in-game performance.
- Direct icing. The palm is cooled with ice or near-freezing water. Used in several of the baseball studies, and useful precisely because it exposes the limits of going too cold.
The parameters that make palm cooling work
Across this body of research, a few specific variables have emerged as the keys to effective palm cooling:
- The Cooling Site. The effect depends on cooling glabrous skin — the palms, soles, and face — where arterio-venous anastomoses (AVAs) allow large volumes of blood to be cooled quickly. The palms are the most practical of these.
- Temperature. Colder is not automatically better. Below roughly 50°F (10°C), the vessels vasoconstrict and shut off the very blood flow you are trying to cool, and cooling that causes pain can erase the performance benefit entirely (see the Lin baseball study). The recurring sweet spot for repeated performance and recovery use is Cool-not-Cold, about 50–60°F (10–15°C).
- Conductive contact. Heat moves out of the blood only while the palm is in sustained contact with the cool medium.
- Duration and continuity. Cooling can run continuously during exertion or intermittently between sets, innings, or rounds. Longer applications (10+ minutes) suit heat-stress recovery; shorter ones suit in-game use.
- Pressure. Adding subatmospheric pressure can help fill the venous plexus in the palm, though at least one study found its added benefit modest under the conditions tested.
Heat Stress Mitigation
Heat Loss Through the Glabrous Skin Surfaces of Heavily Insulated, Heat-Stressed Individuals
Cooling the palms and other glabrous skin surfaces accelerated core temperature recovery in subjects who were heat-stressed while wearing heavy insulating clothing. Grahn, Dillon & Heller (2009), Journal of Biomechanical Engineering.
Prevention of Heat Strain by Immersing the Hands and Forearms in Water
Immersing the hands and forearms in cool water (tested at 10, 20, and 30°C) significantly lowered core temperature within ten minutes and reduced heat strain in personnel working in fire-fighting clothing — and the colder the water, the faster they cooled. House, Holmes & Allsopp (1997), Journal of the Royal Naval Medical Service.
Forearm submersion during rest breaks lowered heart rate and core temperature and extended firefighters' work tolerance compared with misting or passive rest. Selkirk, McLellan & Wong (2004), Journal of Occupational and Environmental Hygiene.
Cold Water Immersion of the Hands and Feet for Cooling Hyperthermic Individuals
Hand and/or foot immersion in 10°C water effectively lowered core temperature in hyperthermic subjects who had exercised in protective clothing, with hand immersion most effective over longer periods. McTiffin & Pethybridge (1994), Proceedings of the 6th International Conference on Environmental Ergonomics (conference paper; no DOI).
Aerobic Capacity
Extracting heat through the palm slowed the rise in core temperature during treadmill exercise in a 40°C environment and substantially increased how long subjects could keep going. Grahn, Cao & Heller (2005), Journal of Applied Physiology.
Resistance Training
Palm cooling between sets increased training work volume (bench press ~40%, pull-ups up to ~144%) and raised one-rep-max strength ~22% over the training period. Grahn, Cao, Nguyen, Liu & Heller (2012), Journal of Strength and Conditioning Research.
Some resistance training studies which have focused on lower volume, less than 4 sets of a given exercise, or shorter (e.g., ~1-minute cooling breaks) have shown little or no benefit to palm cooling. For resistance training, the real benefit of palm cooling appears to be in the ability to add significantly more work volume, while still recovering well between sessions. The added work, week over week, compounds quickly. For resistance training a 3 minute cooling break appears to be the sweet spot.
Sports Specific
Use of Gloves to Examine Intermittent Palm Cooling's Impact on Rowing Ergometry Intermittent palm cooling delivered through cooling gloves lowered heart rate and blood lactate and increased distance rowed across an ergometer workout. O'Brien, Kozerski, Gray, Chen, Vargas, McEnroe, Vanhoover, King, Pantalos & Caruso (2021), Journal of Strength and Conditioning Research.
Intermittent palm cooling improved throwing velocity and accuracy in baseball athletes who felt no pain from the cooling, but reversed and impaired performance in those for whom the cooling was painful. Lin, Huang & Cai (2025), Journal of Human Kinetics.
Basic Research on the Effect of Icing on the Palm for the Prevention of Pitching Injuries
Cooling the palm between sets across nine simulated innings helped maintain shoulder external-rotation strength and limited the loss of throwing-arm external rotation associated with pitching injury. Miyashita, Hariki, Koyama, Okamune & Horibe (2022), Japanese Journal of Athletic Training.
Effect of Icing the Palm After Loaded Shoulder External Rotation on Strength and Range of Motion
Cooling the palm after fatiguing shoulder external-rotation exercise helped restore external-rotation strength without the loss of internal-rotation range of motion that icing the shoulder directly can cause. Miyashita, Hariki & Horibe (2021), Japanese Journal of Athletic Training.
How It Works: The Foundational Science
Arterio-venous Anastomoses in the Human Skin and Their Role in Temperature Control
A physiology review of the AVAs — the direct artery-to-vein connections in the palms, soles, and face — and how the body uses them as radiators to control whole-body temperature. This is the mechanism every study above is ultimately taking advantage of. Walløe (2015), Temperature.
