Ice packs spend 9 minutes doing their job. Kelvin™ spends 40.
Time held in the optimal 10-12°C cooling range. Independently verified.
A fridge-ready cold compress that holds the temperature physio's actually recommend - 10-12°C, steady, for 40 minutes. No freezer. No ice burn.
PCMx™ is a phase-change material: the same latent-heat principle used in aerospace thermal regulation. It absorbs heat by changing state rather than warming up, holding the optimal therapeutic window for up to 40 minutes, roughly four times longer than a frozen gel pack stays useful.
Safe against bare skin. No cloth barrier, no shocking cold, no ice burn. The sewn-edge indicator badge turns blue when it's ready.
Hand-finished sport-grade flex-shell, sealed PCM pods, sewn-edge indicator badge. Designed in the UK, made to outlast the injury that brought you to it.
Ice blue in the optimal window. Fades to white when it's time to recharge.
No fabric, no fleece, no insulating layers between you and the cold. A 5mm sport-grade flex-shell holds twelve sealed PCM pods (60×60mm) in a 4×3 grid that bends where your body bends, with a sewn-edge indicator badge integrated into the pad edge.
From 50-something knees to weekend rugby strains: cooling held where the tissue actually responds, for as long as it takes to feel different.
Controlled cooling comfort for knees and joints after long days, workouts or everyday stiffness.
Fridge-ready cooling for lower back comfort while resting, sitting or winding down.
Sits over the joint without compressing the nerve. 40 minutes, repeatable through the day.
Keep Kelvin™ in the fridge so controlled cooling is ready when you need it.
Wraps over the shoulder and stays put for 40 minutes of steady cooling after tennis, golf, swimming or a heavy gym session.
Steady cooling after runs, training or gym sessions, without the freezing shock of a frozen pack.
Kelvin™ is intended for general cooling comfort and recovery support. It is not a substitute for medical advice. Always follow the instructions for use.
Pop Kelvin™ in the fridge for 60-90 minutes. The sewn-edge indicator badge turns ice-blue when it's ready.
Rest the bare flex-shell directly against the skin - calf, lower back, between knees, on top of a shoulder. No fabric layer, no barrier, maximum cold transfer.
Hold at 10-12°C for up to 40 minutes. Pop it back in the fridge. Use it again later. And later.
"Standard ice packs shouldn't touch your skin directly."
Because they're sub-zero. Kelvin™ never goes below 10°C, so it's designed to be worn against bare skin, with no cloth barrier and no risk of ice burn.
Ready to feel the difference?
One Kelvin™. Every ache. £39.
Drop tissue too cold and the Lewis hunting reaction kicks in: vasoconstriction flips to vasodilation, and the treatment starts working against itself. Modern evidence points to a controlled 10-15°C, held steady. Kelvin™ sits exactly there.
The red pulse on the chart is the only stretch a frozen gel pack is actually in the optimal therapeutic window: about nine minutes, sandwiched between ice-burn cold and useless warm.
Algafly & George, peer-reviewed in the British Journal of Sports Medicine, 2007.
"Cooling skin to 10°C reduced nerve conduction velocity by 33%, with meaningful cooling effect below 13.6°C."
That's the band the modern evidence points to - cold enough to deliver effective cooling, not so cold that the body fights back or the tissue gets injured. Standard ice and gel packs start far below this window; uncontrolled cryotherapy has even been clinically linked to peripheral nerve palsy. Kelvin™ was engineered to live inside the safe, effective range, and stay there for up to 40 minutes.
Reduction in peripheral nerve conduction velocity at 10°C (Algafly & George, 2007).
Threshold for meaningful cooling effect - Kelvin™'s 10-12°C sits squarely inside it.
Where standard ice and gel packs start - outside the optimal therapeutic window, and linked in case reports to nerve injury.
Gel and ice packs come out of the freezer at sub-zero temperatures, which is too cold for therapeutic cooling. Kelvin™ uses PCMx™ - a phase-change material that absorbs heat by changing state - to hold a steady 10-12°C (the temperature physios actually recommend) for up to 40 minutes.
No. Kelvin™ recharges in a normal fridge in about 60-90 minutes. The sewn-edge indicator badge turns blue when it's ready to use.
Yes. Kelvin™ is designed for direct skin contact when used as directed. Unlike frozen packs, it does not need to be frozen and is designed to avoid the harsh sub-zero shock associated with freezer gel packs.
Kelvin™ is intended for external cooling on intact skin. Do not use if you have reduced skin sensation, poor circulation, cold sensitivity, nerve damage, or if a clinician has advised you to avoid cold exposure. Speak to a healthcare professional if unsure.
Kelvin™ is designed for supervised cooling sessions while resting or sitting. Do not use while asleep.
Up to 40 minutes inside the optimal therapeutic window - roughly three to four times longer than a standard ice pack stays useful.
PCMx™ is designed to hold at 10-12°C, well above freezing. Unlike frozen gel packs, Kelvin™ is designed for direct skin contact when used as directed, with no towel barrier required. Ice burn was the single most frequent complaint we found across 146,000 reviews of category-leading cold packs. It's the first problem Kelvin™ was designed to solve.
A sewn-edge thermochromic indicator badge integrated into the pad edge stays ice blue while Kelvin™ is inside the 10 to 12°C therapeutic window, then fades to white when it needs to recharge. No guessing, no thermometer.
The 5mm sport-grade flex-shell outer wipes clean and contains surface condensation, with twelve sealed PCM pods inside. No drips on your skin, your sofa or the bed.
Yes. The pods are arranged in a 4×3 grid with five independent flex axes, so it forms around knees, shoulders, ankles and the lower back without rigid edges.
Yes. Kelvin™ recharges in any fridge in 60 to 90 minutes, which is fast enough for multiple sessions in a day. No freezer required, so it works in an office or hotel room.
30 days, no questions asked. If Kelvin™ isn't for you, send it back for a full refund.
