Everyday
Lower back
Fridge-ready cooling for lower back comfort while resting, sitting or winding down.
An ice pack is cold enough to burn you.
Straight from the freezer it is around -15°C, an ice-burn risk on bare skin.
Kelvin® holds a controlled 10 to 12°C, straight on.
Cold, held steady.
A reusable, fridge-ready cold-therapy pad that holds a gentle, controlled 10 to 12°C, the range used for cold therapy, instead of the around -15°C of a pack straight from the freezer. It never freezes solid and never goes sub-zero. Fridge charged, controlled cold, reusable with no ice-burn.
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Steady 10 to 12°C
Never sub-zero
No meltwater
- Steady 10 to 12°C
- Never sub-zero
- No meltwater
Prep
Charge it in your fridge
Overnight is easiest. The badge shows when it is ready.
Apply
Strap it in place
Use firm, normal pressure on a knee, elbow or lower back.
Reuse
Steady 10 to 12°C
Use it for a full cold-therapy session, then recharge.
Why not an ice pack?
Kelvin® vs ice packs.
An ordinary ice or gel pack comes out of a domestic freezer at around -15°C, around 25 degrees colder than the range where cold therapy works. That is far too cold at first contact: it carries an ice-burn risk, numbs the skin, and can trigger the body's cold rebound, flooding the area with warm blood that cancels the relief. As it thaws, it passes through the useful range and keeps warming. It also sweats and drips.
Kelvin® begins in the cold-therapy window and holds a gentle 10 to 12°C as it slowly warms. It never goes sub-zero, so it is designed to avoid ice-burn and cold shock. The phase-change material melts and re-freezes sealed inside the pods, so there is no meltwater to drip or soak into your clothes.
Feature
Recommended
Kelvin®
Alternative
Ice / Gel
Recommended
Kelvin®
Alternative
Ice / Gel
Application temperature
Application temperature
10 to 12°C
Around -15°C
Cold-therapy range from first contact
Cold-therapy range from first contact
Yes
No
Ice burn risk
Ice burn risk
Designed to avoid ice burn when used as directed
Can cause ice burn on direct skin contact
Through a full session
Through a full session
Steady in range
Warms through the range
Recharge
Recharge
Fridge, ready overnight
Freezer required
Fits the body
Fits the body
Flexible, 30 x 40 cm
Often rigid
"Do not apply ice directly to the skin."
Because a frozen pack starts at around -15°C, far too cold at first contact. Kelvin® never goes sub-zero, so it is designed to avoid the ice-burn and cold-shock of a pack that starts sub-zero when used as directed.
Cold that helps is steady, not shocking.
In-house thermal comparisonThe difference,
The difference,
in infrared.
A thermal camera makes the comparison plain. A frozen ice pack begins at around -15°C, far below the useful range. Kelvin® comes from the fridge and warms gently through the comfort window.
Who Kelvin® is forBuilt for the bodies
Built for the bodies
that keep moving.
For active days, training sessions and everyday routines, Kelvin® provides gentle, controlled cooling that fits around the body.
Shoulders
Sits over the shoulder for steady cooling after tennis, golf, swimming or a gym session.
Everyday
Knees & joints
Controlled cooling comfort for knees and joints after long days, workouts or everyday activity.
Tennis elbow
Flexible cooling that sits comfortably over the joint and can be recharged for another session.
Amateur sport
After training
Steady cooling after runs, training or gym sessions, without the freezing shock of a frozen pack.
Kelvin® is intended for general cooling comfort. It is not a medical device or a substitute for medical advice. Always follow the instructions for use.
Shop now, from £39Free UK shipping · 30-day returns
Considered detailBare-shell.
Bare-shell.
Direct cold transfer.
No fabric, no fleece, no insulating layers between you and the cold. A matte black sport-grade flex-shell holds thirty-five heat-welded phase-change pods in a 7 x 5 grid that bends with the body, with a thermochromic readiness badge on the pad edge.
- Dimensions
- 30 x 40 cm · 7 x 5 pod grid (35 pods)
- Phase point
- 10 to 12°C
- Outer
- Matte black sport-grade flex-shell
- Construction
- Heat-welded TPU pod grid, thermochromic readiness badge
- Recharge
- Fridge charge, ready overnight
From our first users
“It's amazing, it really helped my back. Perfect size, didn't irritate my skin at all, and it didn't get wet at all. I really like the product.”
“It's great. Not a shocker to the system when you apply it.”
“I loved the fact there was no risk of ice-burn for my kids.”
Individual experiences. Kelvin® is intended for cooling comfort and is not a medical device.
How it works
Chill. Apply. Recharge.
01Chill
Charge Kelvin® in your fridge. Overnight is easiest. The readiness badge tells you when it is set.
02Apply
Strap it to a knee, elbow or lower back with firm, normal pressure.
03Recharge
It holds a gentle, controlled 10 to 12°C for a full cold-therapy session, then you recharge and reuse it. It is not designed to be sat or lain on, which drains it faster.
The system
01The principle · phase-change material inside
Latent-heat physics. Held at 10 to 12°C.
A phase-change material absorbs heat by changing state rather than simply warming up, helping Kelvin® hold a gentle, controlled temperature through a full cold-therapy session.
02 Always know
The badge tells you when it is ready.
Ice blue when ready. Fades to white when it is time to recharge.
03 Fridge charged
Fridge charge, ready overnight.
Kelvin® never goes sub-zero, so it is designed to avoid the ice-burn and cold-shock of a frozen pack, which starts at around -15°C. The readiness badge shows when it is ready.
04 Family safe
Fridge cold, never sub-zero.
Charged in the fridge, not the freezer, so it is designed to avoid ice burn. Comfortable for the whole family.
The science has moved onCold therapy
Cold therapy
has a useful
temperature range.
Cold therapy works by cooling the skin into roughly the 10 to 15°C range, which slows local nerve signalling. In one study, cooling the skin to about 10°C reduced nerve conduction velocity by about a third.
Go colder and there are diminishing returns and rising risks, including ice-burn and the cold rebound first described by Lewis in 1930. Colder is not always better.
About the name: the kelvin is the scientific unit of temperature, with zero set at absolute zero. It is the scale used when temperature has to be measured precisely, which is the idea Kelvin® is named for.
Kelvin® Frozen ice / gel pack
Fig. 01 · Illustrative temperature profileIllustrative, based on our own thermal testing. A frozen pack sits sub-zero, an ice-burn risk, before slowly warming past the useful range; Kelvin® stays in the controlled cold-therapy window. Independent thermal testing is underway and measured figures will be published here when it is complete.
From the evidence
Algafly & George, peer-reviewed in the British Journal of Sports Medicine, 2007.
"Cooling skin to about 10°C reduced nerve conduction velocity by about a third."
The benefit comes from holding the useful temperature window. A melting ice pack cannot hold one temperature, while Kelvin® is designed to settle into a gentle 10 to 12°C as it slowly warms.
Reduction in nerve conduction velocity at about 10°C in Algafly and George (2007).
The approximate skin-temperature range used for cold therapy.
Where frozen gel and ice packs start when they come out of a domestic freezer, before warming through the useful range.
Ready for controlled cooling?
One Kelvin®, ready when you are. From £39.
FAQ
Questions, answered.
How is Kelvin® different from a normal gel pack?+
Gel and ice packs come out of a domestic freezer at around -15°C, far too cold at first contact, then warm through the useful range. Kelvin® uses a phase-change material to hold a gentle, controlled 10 to 12°C as it slowly warms.
What's behind the name?+
The kelvin is the scientific unit of temperature, named after the physicist Lord Kelvin. Its zero point is absolute zero, the coldest anything can be, and it is the scale used when temperature has to be exact. That precision is the idea behind the product: Kelvin® is built around a temperature window, 10 to 12°C, not around how cold a pack can feel.
Do I need a freezer?+
No. Charge Kelvin® in your fridge; overnight is easiest. The readiness badge shows when it is set.
Can I put it directly on my skin?+
It never goes sub-zero, so it will not ice-burn the way a frozen pack can. Use it as directed.
Who should not use Kelvin®?+
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.
Can I sleep with Kelvin®?+
Kelvin® is designed for supervised cooling sessions while resting or sitting. Do not use while asleep.
How long does each use last?+
It holds the cold-therapy range for a full session. We are having the exact figure measured by an independent laboratory and will publish it here.
Won't it give me ice burn like a frozen gel pack?+
Kelvin® never goes sub-zero, so it is designed to avoid the ice-burn and cold-shock of a frozen pack. Use it as directed.
How do I know it's actually at the right temperature?+
A thermochromic readiness badge on the pad edge shows when Kelvin® is ready, then fades when it needs to recharge.
Does it leak or sweat onto my skin and furniture?+
The phase-change material melts and re-freezes sealed inside the pods, so unlike a thawing ice pack there is no meltwater to drip. Taken straight from a cold fridge into a humid room the outer surface can bead with a little condensation, which clears as it settles to temperature. In normal use, on the body, it stays dry. The sport-grade flex-shell outer wipes clean and holds thirty-five sealed phase-change pods.
Will it fit a curved joint like a knee or shoulder?+
Yes. The pods are arranged in a 7 x 5 grid so the pad forms around knees, shoulders, ankles and the lower back without rigid edges.
Can I use it more than once a day?+
Yes. Recharge it in the fridge after use. The badge shows when it is ready for another session.
What's the return policy?+
30 days, no questions asked. If Kelvin® isn't for you, send it back for a full refund.
