A fridge-ready cold wrap that holds the temperature physio's actually recommend - 10-12°C, steady, for 40 minutes. No freezer. No ice burn.
“Finally a pack that doesn't numb me out. Forty minutes goes by quietly.”
“I tell every patient to take ice packs out of the freezer 20 min before. Kelvin just does this properly.”
“Lives in my fridge, comes out daily for my shoulder. Bought a second one for my mum.”
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 thermochromic strip turns blue when it's ready.
Hand-finished neoprene shell, soft microfibre interior, sealed PCM pods. Designed in London, 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.
A 140-160 GSM OEKO-TEX microfibre face that sits soft against the skin. A 5mm neoprene shell that insulates against the room. Twelve heat-welded TPU pods (60×60mm) quilted into a 4×3 grid that bends where your body bends.
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.
Wraps 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.
Quads, calves, delts after a hard session. Reduce soreness without the rebound swelling.
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 thermochromic strip turns ice-blue when it's ready.
Rest it directly against the skin - calf, lower back, between knees, on top of a shoulder. The grid drapes; the neoprene insulates.
Hold at 10-12°C for up to 40 minutes. Pop it back in the fridge. Use it again later. And later.
| Kelvin | Standard ice / gel | |
|---|---|---|
| Application temperature | 10-12°C | 0°C or below |
| In the optimal therapeutic window from first contact | Yes | No |
| Ice burn risk | Designed to avoid ice-burn risk when used as directed | Can cause ice burn if applied directly to skin |
| Therapeutic duration | Up to 40 min | ≈ 10-15 min |
| Recharge | Fridge · 60-90 min | Freezer · 2-4 hrs |
| Fits the body | Flexible 4×3 grid | Often rigid |
"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 wrap. 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.
I used to dread icing my knee. Kelvin is genuinely comfortable - and I can actually feel it working without that shocking cold. Forty minutes goes by quietly.
It solves the exact problem I see with frozen packs - they often start too cold and uncomfortable.
Shoulder and neck after a long writing day. It drapes, it stays put, it doesn't make me shiver. I bought a second one for my mum.
From everyday joint pain to post-run knees.
“Bought the twin pack so one's always cold. Worth every penny for the shoulder flare-ups.”
“Recommended by my physio. The temperature really does stay steady, unlike a frozen gel pack.”
“Trio lives between the fridge, gym bag and bedside. Best £99 I've spent on recovery.”
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 thermochromic indicator 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.
No. PCMx™ never drops below 10°C, so Kelvin sits directly against bare skin with no cloth barrier needed. 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 thermochromic strip on the wrap 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 neoprene outer absorbs surface condensation, and the twelve PCMx pods are heat-welded TPU. 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 the wrap 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.
