KELVIN° · Premium in-race cooling
Cool head.
Higher ceiling.°
Your body quits before you do. Stick KELVIN on your neck and keep your grip in the second half, when everyone else fades.
In stock · Delivered in 3-5 working days · 14-day returns on unopened packs
- +10.5% distance*
- 4 hours cooling, guaranteed
- Peel, stick, cool
- Stays on while sweating
*Study with a neck cooling collar in a heat time-trial, Eur J Appl Physiol.
Honest note: KELVIN works through heat perception and central fatigue. It does not claim to lower your core temperature and is not a medical device.
The problem
The brake is in your brain
Above 39-40°C core temperature, your nervous system throttles your muscles to protect you. Your pace drops, your heart rate spikes and your head still wants more. That is not weakness. That is a brake.
“My body hits the brakes while my head still wants it. In the second half my pace drops and there is nothing I can do.”
“I keep my grip. I keep pushing while the rest fades. The ceiling is gone.”
How it works
Peel. Stick. Cool.
Peel off the film, stick it on, and it activates automatically. No towel, no melting ice.
Peel off the film
Peel the protective film off the patch.
Stick it on
Place the patch on the back or side of your neck, over the large blood vessels that carry the cold signal straight to your brain.
Keep pushing
It activates automatically and keeps cooling for 4+ hours. The cold signal lowers your head perception, so your brain gives the green light to keep working at the same effort.
4+ hours of cooling
Built to outlast your race
Stick it on before the start. It activates automatically and keeps cooling for more than 4 hours.
Marathon
42.2 kmCooling through the second half, when the heat and the fatigue stack up.
Hyrox
8 × 1 km run + 8 stationsCooling from the first run to the wall balls.
Triathlon
Swim · Bike · RunStage positions based on typical time per leg.
Ultra trail
50 km+ · 6+ hoursAt least 4 hours of cooling guaranteed, often 6 to 8 hours in our own tests. On longer ultras, bring a spare patch for a later aid station.
In stock
Choose your pack
One patch per race. Start with one, or stock up for the season.
Delivered in 3-5 working days · 14-day returns on unopened packs
Disciplines
Built for the second half
Hyrox
Indoor heat and heavy stations. Stick it on before the start and hold your pace to the wall balls.
Marathon
The heat stacks up after halfway. Stick it on before the start and keep your grip in the second half.
Triathlon
Off the bike and straight into the heat. Stick it on in T2 and run with a cool head.
From the start line
Athletes on KELVIN
“PR on my first hot ultra. It kept me cool past km 60.”
“Sub-1:35 and a new PR.”
At 12 km, when it got hard, the KELVIN patch was still keeping me cool. It pulled me through the toughest stretch of the Rotterdam Half. Couldn't be happier with the result.
Your next race is hotter than you think.
Order nowIn stock · Delivered in 3-5 working days · 14-day returns on unopened packs