DEFINITION

WHAT IS PALM COOLING?

Palm cooling means holding something cold, not too cold, in your hands in the rests you already take, so that heat leaves your body through the palms, where it leaves easiest.

The science behind it →Compare the devices →

Most of your skin holds heat in. Your palms let it out.

Inside your palm

You are cool
The heat vessels stay shut. Heat stays in.
↓→
You are warm
The heat vessels (AVA) open, a shortcut from artery to vein, and the heat wants out. Air carries it away slowly.
↓→
Warm, holding something that conducts heat
It pulls the heat out fast. Colder is not better. More contact is.

Heat vessels (AVA*) are shortcuts between artery and vein. They feed no tissue. They only move heat. That is why what you hold should be cold, not too cold. Cold from the fridge, not straight from the freezer. The full mechanism, with figures: How it works →

*Arteriovenous anastomoses. How they work: Walløe, 2015. Temperature.

Where does palm cooling come from?

The idea comes from Stanford. In 2005, Dennis Grahn, Craig Heller and a colleague cooled the palm during exercise in the heat, with a device that also applied suction, and people kept going longer. The hand device that came out of that work was developed and tested under a programme funded by DARPA, the research agency of the US Department of Defense. More than twenty independent studies have followed, none funded by us.

2005Stanford

20+independent studies since

Does palm cooling work?

Cooling the palms between efforts lets people do more work before they tire. In the most recent strength study, fourteen trained men lifted 22% more in total across their sets with palm cooling than without, and 15% more than with a placebo.

WANG ET AL. 2026 · 14 TRAINED MEN · NOT A KYLA STUDY

Shown, in independent studies

More reps in the later sets.
More repeated sprints.
A longer time to exhaustion.
At a lower perceived effort.

Not shown

A bigger single maximal lift.
The same result every time. Two studies found a worse result.
A published study on KYLA's own handles. One starts testing in January 2027.

Most studies point the same way, but they are small and the size varies. Published research → Our testing so far →

What kinds of device are there?

Ice and gel packs Start too cold, then warm through the useful range and past it.

Water-filled metal bars Good contact at first, but the water behind the shell warms with every grip.

Phase-change cores Hold the surface at one temperature until the core has melted through. Ours is one of them.

Battery-powered handhelds The hot side has nowhere to dump its heat, so each palm gets only a little moved.

Stationary systems High output for hours, in one place.

What separates them is how fast they take heat out of the palm, and for how long. Nine devices side by side, on the makers’ own numbers:

How to choose a palm cooling device →

Common questions

Does palm cooling lower core temperature?In some studies, yes: a smaller rise across the session. In others core temperature did not differ, even when people did more work.

It does not make you cold; it removes heat the body is already trying to shed.

Why not a cold bottle?A bottle is made to hold a drink, not to move heat.

It can take little heat out of the palm, and what it can take fades as it warms in your hand.

Does it work for strength training or only endurance?The clearest results are in strength training, where output is counted in reps across sets.

Endurance and repeated-sprint studies show the same direction.

Is it the same as an ice bath?No.

An ice bath cools the whole body from the outside, after training. Palm cooling removes heat through the blood, and its main slot is between efforts, during the session, where the heat is being made. Ice bath vs palm cooling.

Is palm cooling safe?Most people, yes.

Check first if circulation or hand sensitivity is a concern.

How do you use palm cooling?One in each palm, 60 to 90 seconds, every rest.

Cold from the fridge. How to use it →

Or start with ours.

A pair of handles for the rests you already take. A full session per chill, nothing to charge.

Reserve a pair, ships 10 November 2026

$345.00 · $34.50 today · 90-day returns