Cool head. Higher ceiling.
Your body quits before you do. Above 39-40C core temperature, your nervous system throttles your muscles to protect you: pace drops, heart rate spikes, and your head still wants more. That is not weakness. That is a brake.
KELVIN is a stick-on cooling element you snap to activate on your neck, so you keep your grip while everyone else fades in the second half.
Proof, not hype
Neck cooling works mainly through perception. It lowers the heat signal to your brain and delays central fatigue, so you push harder at the same effort.
- +10.5% distance. Runners covered 3,030 m with neck cooling versus 2,741 m without, in a heat time-trial. Source: Practical neck cooling and time-trial running performance, Eur J Appl Physiol
- The brake is central. Above 39-40C your nervous system cuts muscle efficiency to prevent overheating.
- The neck is the spot. High thermoreceptor density near large blood vessels makes it the fastest signal to your brain.
- Honest note: KELVIN improves performance and your sense of grip through heat perception and central fatigue. It does not claim to lower your measured core body temperature, and it is not a medical device.
Choose your format
Which format is right for you?
Three ways to run KELVIN — pick by race length and how much active cooling you need.
KELVIN ONE
Single-race starter. Try it on your next event.
- ›3 elements
- ›~30 min active cooling each
KELVIN PRO
Longer cooling for ultra and trail.
- ›3 PRO elements
- ›~45 min active cooling each
KELVIN PACK
Season multipack. The lowest price per race.
- ›10 elements (mixed ONE + PRO)
- ›Lowest price per race
How it works
Snap. Cool. Go.
One deliberate move, right when you choose. No towel, no melting ice. A switch.
Stick it on
Place the element on your neck near your thyroid, the thermostat of your body, fixed with the thin elastic sports tape.
Snap to activate
Break the element so it turns fresh inside. Cooling starts on demand, exactly at the moment you decide.
Keep pushing
The cold signal lowers your head perception, so your brain gives the green light to keep working at the same effort.