How long does a cold therapy machine stay cold?

Breg lists 6-8 hours for its Cube and Kodiak and up to 13 hours for its Glacier per fill.

Do I need a prescription for a cold therapy machine?

Breg says its devices are sold by or on the order of a medical professional.

Does cold therapy help after knee replacement?

A Cochrane review found low-certainty evidence of small reductions in blood loss and pain.

Can the pad touch my skin?

No. Breg says use an insulation barrier between the pad and the skin.

Is a cold therapy machine better than ice?

It gives steady cold with less effort after surgery; for minor injuries an ice pack is simpler. Either way, keep a barrier between the cold and your skin.

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Cold therapy machine

By the Life in Good Form editors. Updated 2026-10-15.

We research products from makers' specs and health sources; we do not run hands-on tests. Links to Amazon may earn us a commission at no cost to you. How this works.

Quick answerA cold therapy machine pumps ice water from a cooler through a pad wrapped around a joint, giving steady cold for hours, often after knee or shoulder surgery. Breg says its Polar Care Cube and Kodiak run 6-8 hours on ice and water, and its hospital Glacier up to 13 hours; Breg also says these devices need an insulation barrier between pad and skin and are sold only by or on the order of a medical professional. A Cochrane review after knee replacement found cold therapy may slightly reduce blood loss and pain, with low-certainty evidence. Follow your surgeon's instructions.

Our picks at a glance

Circulating cold therapy unit with knee pad. Best for: Steady cold after knee surgery, as your surgeon directs. See options on Amazon
Cold therapy machine with shoulder pad. Best for: Shoulder surgery recovery. See options on Amazon
Reusable gel cold pack. Best for: Minor sprains and everyday soreness. See options on Amazon

Compare the picks and what to watch out for

How a cold therapy machine works

Unlike an ice pack, a cold therapy machine keeps cold water moving. You fill a cooler with ice and water, and a small pump circulates it through a pad wrapped around the joint. Breg describes whisper-quiet pump technology and WrapOn pads shaped to conform to areas such as the knee, shoulder, ankle and back.

Some models add features: Breg says its Kodiak offers a battery pack option, and its Glacier has a temperature control dial for individualized settings and a once-a-shift fill designed for 8 or 12 hour hospital shifts.

Breg Polar Care units compared

Unit	Cold time per fill	Notable feature
Polar Care Cube	6-8 hours	Compact; clinic, hospital and home use
Polar Care Kodiak	6-8 hours	Battery pack option
Polar Care Glacier	Up to 13 hours	Temperature control dial; hospital use

Details are from Breg product pages. Breg notes that federal law restricts these devices to sale by or on the order of a medical professional, so your surgeon or clinic usually arranges one.

What the research shows after knee replacement

A Cochrane review of 22 trials with 1839 people after total knee replacement found low-certainty evidence that cold therapy may reduce blood loss: 825 mL without cold therapy versus 561 mL with it, a mean of 264 mL less, in 12 trials with 956 participants. Evidence for pain and range of motion was also low certainty.

The trials compared cold with compression against no treatment (4 studies) or compression alone (9 studies), and cold without compression against no treatment (8 studies). Participants' mean ages ranged from 64 to 74 years.

The authors concluded that these potential benefits may be too small to justify routine use, and that they are uncertain about effects on transfusion, function and adverse events. Most studies had a high risk of bias because cold therapy is hard to blind.

Using one safely

Always use a barrier. Breg says proper use requires an insulation barrier between the pad and the skin. Breg sells sterile Polar Dressings for this.
Follow your surgeon's schedule for how long and how often to use cold, and the device instructions for use.
Check your skin under the pad regularly for numbness, color change or blistering, and stop if you see them.
Take extra care if you have diabetes, poor circulation, numbness or sensitivity to cold, and ask your care team first.
Keep dressings dry as your surgeon directs.

Machine or ice pack?

A machine offers steady cold with less effort after surgery, which is why Breg pitches its units for post-operative arthroscopic procedures. For minor sprains, sore knees or everyday aches, a reusable cold pack is simpler; see our ice pack for knee guide, shoulder ice pack guide and gel ice packs guide.

Whichever you use, a cold source should never sit directly on bare skin.

Pads and fit

Match the pad to the joint. Breg lists WrapOn pads for the knee (including large and XL), shoulder, ankle, back and multi-use areas.
Long stem pads. Breg lists a multi-use pad with a 16 inch long stem for reaching from the cooler.
Single patient use. Breg describes its combo units as including one single patient use pad.
Ask how it is supplied. Because these are ordered by a medical professional, your surgeon's office can tell you how to get your unit and pads.

What to look for when you buy

Circulating cold therapy unit with knee pad

Best for: Steady cold after knee surgery, as your surgeon directs

Breg lists 6-8 hours of cold per ice and water fill on its Cube and Kodiak units with knee pads.

Watch out: Use an insulation barrier and follow your surgeon's schedule.

See options on Amazon