After doing 35 hours of research, interviewing experts, and testing temperature reduction on the body parts of two different people, we think the Thermipaq Hot/Cold Pack is the best cold pack for most people. It’s the only cold pack we tested that cooled skin to the ideal temperature every time, making it more comfortable than the competition.
Testing these products proved that the coldest packs weren’t the best choice. Achieving full pain relief requires an absolute skin temperature of 12°C (54°F)—and the coldest packs actually caused pain at this extreme level. We found you really just want to lower skin temperature by 5 to 15°C, from a typical starting point of around 30°C, which is enough to treat inflammation. Doing that for 10 to 15 minutes eases pain by reducing the swelling’s nerve-pinching pressure. For this kind of treatment, the Thermipaq pack is perfect.
The Thermipaq cold pack was the only one that consistently lowered skin temperature by 11 or 12°C, which falls in that perfect cold, but not too cold, range. Of all the packs we tested, most got too cold too quickly, but only the Thermipaq stayed in this ideal zone every time. This made it effective, and considerably more comfortable, than other packs we tested. And it stayed cold for longer than any other pack, holding an effective temperature for up to an hour after being removed from a freezer. Even though you need it to work for only 10 to 15 minutes, this makes it an easier product to use, especially if you’re moving slowly.
Its superior comfort went beyond temperature. Rather than the stiff, very cold gel or clay found in other packs, the Thermipaq ice packs have fluid-filled spheres that can conform to any shape, even right out of the freezer. This versatile design lets its 8- by 10-inch cuff surround and compresses a limb or drape over a sore shoulder. It’s also convenient—unlike most of the other cold packs, the Paradice’s soft spandex shell doesn’t require a towel barrier for preventing ice burns or soaking up messy condensation.
If you can’t get the Thermipaq, the Paradice was the second-best choice we tested. Though the extra-large, 9.5- by 16-inch pack we tested was a bit cumbersome, especially when trying to isolate the ankle for icing, the clay inside it molds nicely around the body. This was the only pack we tested that has Velcro straps built in to its microfiber pouch, which help keep it in place and supply compression (with the others, you’ll often need an elastic Ace bandage). The pack lowers tissue temperature by about 15°C, which is within an effective range for therapy, and its microfiber pouch prevents ice burn. However, the pack got uncomfortably cold compared with the Paradice, and it tended to get stiffer—fresh out of a few days in the freezer, it required some massaging before we could mold it to a body part.
A Simple Gel Pack
- Remains flexible when frozen!
- Stays cold longer!
- Can be used for both cold and heat therapy
- Strong, durable, and reusable!
If you absolutely want something cheap and cold, get a gel pack from Accurate Manufacturing, which makes the coldest ice packs of the all the ones we tested. The gel was still fairly pliable after freezing, and the 6- by 10-inch pack held its temperature very well—its surface temperature remained nearly constant when exposed to air for 15 minutes, even when placed in a microfiber pouch (not included). Though the body parts we tested (ankle and bicep) started to become numb toward the end of the experiment, there were no signs of cold burn on the skin. And at less than $7, it’s tough to beat the price. However, it isn’t nearly as comfortable to use as our pick and runner-up—it just gets too cool, and it leaves the skin red after use.
When people experience a bruise or a sprain, doctors recommend the PRICE principle: protect, rest, ice, compress, elevate. The “ice” part, also called cryotherapy, simply means reducing the temperature of the skin in a small area to treat a soft tissue or bone injury. The cold temperature restricts blood flow, preventing blood from pooling in the area where the injury occurred. The chill reduces the metabolism of the surrounding tissue, which limits inflammation, and, if cold enough, can slow nerve function, numbing the pain.
According to experts, treating the swelling of an injured area requires a local temperature drop of 5 to 15°C (about 9 to 27°F), while pain relief needs an absolute temperature of at least 12°C (53.6°F). Cryotherapy should feel cold, but not painful. After all, it is pain that you are potentially trying to treat in the first place. If you’ve ever put a Ziploc bag full of ice directly on your skin, you’ll know the discomfort we’re talking about. Most of the packs we sized up were much more comfortable than a bag of ice—and less messy, too, since there were no leaks during testing.
Dr. Joseph Costello, a researcher at the Institute of Health and Biomedical Innovation at Queensland University of Technology, examined the different methods of delivering cryotherapy and found that “Cold water is typically the most efficient method of cooling due to its thermal conductivity.” As Costello told me, the thermal conductivity of water can be three times greater than the thermal conductivity of cold air. However, regulating ice bath temperature can be difficult. Too low of a temperature may cause pain or a dangerous drop in tissue temperature (hypothermia). Even frostbite is a real possibility, which, in extreme cases with cryotherapy, can result in amputation. Implementing this method would require close regulation of the water temperature, because even small changes in the amount of ice added to the bath could have drastic effects on its chill.
Ice packs improve on ice baths by being reusable and cooling tissue within safe temperature ranges. Also, body parts can still be elevated—another component of the PRICE formula—unlike ankles dunked into a bucket of ice water. Another advantage of cold packs is that they’re quick to refreeze. If you’re cycling cold treatment every 45 minutes or so, you can easily run out of ice. With cold packs, simply take the pack out of the freezer and you’re ready to go.
How we picked
Our research showed the ideal cryotherapy pack would be cold enough to treat the injured area in the effective temperature range of 5 to 15°C, while consistently maintaining its temperature for at least 10 to 15 minutes, the recommended icing session time. Our research also showed that once the ice is removed, you should wait at least 45 minutes to an hour before reapplying—so the best pack would have to be able to refreeze in less than an hour. Based on rough price comparisons, we found you should expect to spend about $15 to $20 per pack for reusables. There’s no single ideal size or shape; what you’ll need depends on the injury. The best, most versatile setup would be to have one large cuff and one small cuff, but we decided most people could get by with only one large cuff with plenty of surface area and the ability to mold around different body parts. That led us toward items of about 8 by 10 inches in size.
The next step was determining what medium of cold pack we wanted to recommend. Cold therapy treatment falls into several categories:
Ice bags: The most straightforward cryotherapy method is to apply ice cubes or crushed ice from the freezer to the injured area: Wrap some ice in a towel, seal it in a Ziploc bag (or both) and you’re ready to go. Crushed ice is helpful as it can be tightly molded around the injured area, providing even cooling. The problem with ice, which a cold pack can address, is inconsistent temperature control. It all depends on how much ice is in the bag, how fast it melts, and how much of a barrier there is between the ice and your skin. Plus, as the ice melts, the bag or towel can get wet, which isn’t very pleasant. Ice bags gain points for being cheap and available, and they’re better than nothing in an emergency, but having a dedicated cold pack is more comfortable and convenient overall.
Gel packs: These reusable cold packs can be hit or miss. Some turn solid after freezing, preventing you from conforming the pack around the injured area. Others, such as those made by Chattanooga, remain pliable. The gel itself is often made from either silica, which stays moldable when frozen, or water, propylene glycol, and sodium carboxymethyl cellulose. You should never apply gel packs directly on your skin; a microfiber towel (or even a small bath or kitchen towel) placed between the pack and the skin should prevent the injured area from getting dangerously cold. The gel is encased in a plastic covering, which can sometimes start to leak after several months of use. Even though the pack label says the ingredients are nontoxic, you’ll want to avoid using this around the eyes or mouth.
Instant cold packs: For those who need cryotherapy at a moment’s notice, it’s difficult to beat instant cold packs, such as those made by Dynarex. While stored at room temperature, the bag contains two ingredients: ammonium chloride or ammonium nitrate, and water. A plastic tube or a second bag initially separates the two liquids. When a user squeezes the pack, the ingredients mix together and absorb heat (an endothermic reaction), causing the temperature of the pack to drop. The downsides to these packs are that they have a one-time use, they create waste, and if they leak, the chemical components can cause a burn on the skin. Not fun.
Fluid-filled packs: Newer ice pack technologies use fluid-filled packs to cool the skin. In some of these products, the liquid is encapsulated in small plastic spheres, such as in the Paradice Ice Packs. With Kold-Rite and Arctic Ease, cold water is added to a container in order to rehydrate a stretchy, slimy wrap that cools to a suitable therapeutic temperature, while supplying compression to the injured area. These cold packs are touted as being less painful (and therefore less damaging to the skin) than other cryotherapy treatments. They can also have a more versatile, less stiff shape than other types, and (in our tests) can hold their cold temperatures longer.
Clay packs: These cold packs use a temperature-sensitive clay that is softer than modeling clay. Much like fluid-filled packs (and some gel packs), these cold compresses can be shaped to the injured area. The temperature curves supplied with clay ice packs show that they supposedly hold a lower temperature for a longer period of time than standard gel packs. However, we rigorously tested this claim and did not find much difference between the clay and gel packs. They’re reusable and tend to be more expensive than gel packs.
Cold therapy units: The most expensive cryotherapy treatment (typically a few hundred dollars each) are cold therapy units, which infuse ice water through a compress that wraps around the injured body part. These units are particularly popular following orthopedic surgery; it is unclear how much better they are for less severe soft tissue injuries, so we did not test them.
We looked at existing editorial but didn’t find any comprehensive reviews of cold packs, so we started our search from scratch, looking into more than 50 products and reading buyer reviews to figure out what most people are looking for.
And while the experts we spoke to provided guidance on testing, they didn’t provide usability info on specific cold packs. So we decided to bring in packs of various materials and designs and try them out ourselves. We included a mix of ice, gel, fluid-filled, and clay packs that were available on Amazon and other online retailers:
- Mueller ice bag, large size
- Aqua Calida Ice Bag, small size
- Dynarex Instant cold packs
- Chattanooga Colpac, silica gel, polyurethane gel pack
- Chattanooga Colpac, silica gel, vinyl cover gel pack
- Theramed gel back pad
- Accurate Manufacturing gel pack
- Paradice Packs fluid-filled pack
- Arctic Ease wrap
- Kold-Rite wrap
- Thermipaq, clay icy cold pack
- Thermipaq, hot/cold clay pack
How we tested
We set up our test in two steps: First, we needed to determine how well each cryotherapy method could hold its temperature when left untouched. After preparing each cryotherapy method (i.e., freezing the gel pack, mixing the instant cold pack, etc.), we measured how well the pack held its cold point when exposed to room temperature—because if heat dissipated like this, there was no way it would stay cold enough against warm skin. We took measurements at three different locations on the pack every five minutes for 15 minutes and plotted the mean and the standard deviation of the results.
The four coldest packs that also held their temperature steady (value varying no more than 60 percent during the 15 minutes of testing) were the Paradice Pack, the Accurate Manufacturing Gel Pack, the Chattanooga polyurethane pack, and the instant cold pack.
For the second round of tests, we decided to test the four packs mentioned above, as well as the Thermipaq clay pack, the Arctic Ease cold wrap, and the Kold-Rite cold wrap, since they have different thermal properties than the cold gel packs.
To test how well these seven could cool an injury site on the body, we applied each prepared cold pack on two body parts; one upper body location (bicep: soft tissue) and one lower body location (ankle: joint). When measurements were taken on the same day, they were spaced more than one hour apart—longer than the 45 minutes experts agree you should wait between cryotherapy sessions, and plenty of time for the skin to return to a steady temperature.
Using an infrared thermometer 2 , we took temperature measurements on both the skin/subcutaneous tissue or the joint of the body part where cryotherapy was applied, along with the temperature of the ice pack (which decreased over time after being in contact with body temperature). We averaged readings at three nearby locations every five minutes for 15 minutes. We calculated the mean and standard deviation of the measurements, and plotted the results.
At the same intervals, my wife and I assessed how much pain from cold burn the packs induced, using a five-point scale: one (no pain), two (mild pain), three (moderate pain), four (high pain), five (extreme pain). We also noted other experimental observations, such as skin irritation and numbness.
The Paradice Ice Pack was effective at cooling tissue enough to heal it while remaining very comfortable against the skin. Like the bags of frozen peas that inspired the design, the Paradice can conform to the knobbiest knee or lay flat against the lower back. The lightweight, fluid-filled plastic spheres cool the skin to a temperature that can treat swelling, but the nylon cuff stays dry and comfortable against even sensitive skin. The Paradice received one of the lowest pain scores, with absolutely no redness or numbness on the body part.
The spheres are roughly the size of marbles, which nicely conform to different parts of the body for even compression. This proprietary material (which the manufacturer assured me was nontoxic) has an advantage over competitors’ gel or clay-filled packs: Those can stiffen up once they’ve spent more than a few hours in the freezer, and it’s hard at first to make them conform to a body part. The Paradice pack is immediately flexible, after days in the freezer, even if it freezes while stuffed into a corner or wedged between other items. That was necessary during testing because, after all, it’s a pretty large object for a crowded freezer.
The pack is contained in a soft nylon spandex cloth, which means you don’t need to put a towel in between the cold pack and the skin. By comparison, a lot of other cold packs we tested do not include any insulating bag or cloth—and you’ll definitely need to find something to put between the bag and your skin so you can have an effective, painless experience. The Paradice’s covering did not get wet from condensation during cryotherapy, and it can be washed on the gentle cycle in a washing machine when needed.
The pack refreezes in about 2 hours according to the manufacturer, but in our testing, it reached its coldest temperature in about an hour, which was on par with the other packs we tested. So having one pack on hand will be enough to cycle through cryotherapy sessions, which are supposed to be spaced 45 minutes to 1 hour apart. The reason for the discrepancy in refreezing time might be because the manufacturer claims the packs stay cool for 1 hour.
We tested that claim, and in fact, when exposed to room temperature, the Paradice held its temperature to within 25% of its initial value after 15 minutes. Compared to other packs, the Paradice pack showed far less temperature variation, which means it will be more likely to stay cold during the course of treatment. This may not matter when your icing sessions only last 15 minutes, which is more than enough time for effective cryotherapy. But still, having a pack that stays colder for longer could make it an easier product to use if you’re moving slowly due to an injury.
The Paradice Ice Pack comes in many other sizes, from cuffs to flat packs. We evaluated the P500 cuff, which can be used to surround and compress an injured area during treatment. While the ankle we treated was too small to compress with the p500 cuff, pulling the cuff-shaped spandex pack onto the bicep provided some light compression, which is an important part of the PRICE therapy system. The P500 costs $30, and the others range between $12 and $30, depending on size. Every pack comes with a one-year warranty from the date of purchase.
Aside from testimonials on the company’s website and a brief mention in Self Magazine, to the best of our knowledge, there aren’t other editorial reviews of the Paradice.
Flaws but not dealbreakers
The cuff that we tested was fairly large, and it took up a fair amount of room in the freezer, as it’s the size of a large bag of frozen peas. However, it could be manipulated and stuffed into a tight space fairly easily. A cuff this size can struggle with smaller body parts—in our tests, sometimes the spheres had to be repositioned when tested on the ankle simply because the large cuff was a bit big for that particular body part. The smaller cuff ($15), for instance, would alleviate this problem, as it would fit tightly to the skin, but compared with the larger cuff, it may not be as versatile overall.
As we mentioned earlier, the Paradice doesn’t get cold enough to numb pain directly; only the budget pick Accurate Manufacturing gel pack did that. However, an absolute temperature of 12°C can be painful to keep on the body for 10 minutes, so we don’t see this as a dealbreaker.
If you prefer the solid weight of a chilly clay pack, we recommend the Thermipaq Hot/Cold Pack ($24). The Thermipaq was cold enough to theoretically treat pain directly on the soft tissue of the bicep (the temperature dropped as low as 9°C at one point during the experiment). The pack’s microfiber bag has Velcro straps that you can cinch down to also provide compression (one of the components of the PRICE therapy principle) to keep the pack in place on awkward spots like the lower back.
At 9.5 by 16 inches, the pack is quite large, so it can be wrapped around the thickest limb or draped across the back. The manufacturer claims the pack refreezes in about an hour and still remains pliable, but when we kept the pack in the freezer for several days, it became rigid and needed 5 to 10 minutes at room temperature in order to become malleable once again.
After being out of the freezer for five minutes or so, the clay becomes much more flexible, and you can gently massage it to get an even better fit around the injured body part while icing.
During testing on both the ankle and the bicep, the skin temperature dropped by roughly 15°C on both body parts. That’s definitely at the upper limit of skin temperature drop needed to reduce inflammation—with this pack, you have plenty of coldness to apply to the injury.
The Thermipaq can get your skin cold enough (12°C or 54°F) to theoretically treat pain. However, that low temperature caused moderate discomfort and some skin redness during use, even when the pack was wrapped with a microfiber towel. The Thermipaq received pain scores of three to four, significantly higher than the Paradice Pack. A too-cold pack that you can’t keep on the skin for a full 10 minutes ultimately won’t be as effective on an injury as a more comfortable one.
The website says the material was developed by a NASA engineer, and the pack is comprised of ceramic clay and oil, ideally balanced to facilitate thermal transfer. The clay is patented, so there isn’t much more detail about its properties.
According to the manufacturer, this pack can be warmed in the microwave, but we didn’t speak to experts about the benefits of heat compresses or do comparable testing of its properties as a hot pad.
On Amazon, the pack scored a 4.5 out of 5 stars, with 65 reviews at the time of publication.
The budget pick
One pack that can drop the skin temperature low enough to theoretically numb pain is the Accurate Manufacturing gel pack, which costs only $7, and is 6 by 10 inches, about the size of a bag of frozen peas. It took about an hour to refreeze the pack after use.
The trade-off for cold, once again, was comfort—the Accurate Manufacturing pack scored between three and four on a pain scale (moderate to high coldness), but it was the only other pack besides the Thermipaq that helped the treated site reach a temperature needed to directly treat pain. However, as we previously stated, dropping the skin temperature that low might be counterproductive. The pack’s cover is much thinner than that of other cold packs, so the cold material is closer to the skin, which may be the reason the Accurate Manufacturing pack gets and stays so much colder than comparable products. A towel or microfiber cover (which is not included here) should always be used to protect the skin from redness.
Given how cold it gets, the pack was surprisingly pliable and very easy to mold around both the bicep and the ankle. Its filling is almost like small microbeads which, when frozen, can be molded more easily than a liquid that freezes into a solid brick. Other cheap packs can also get really cold, but they don’t usually have this ability to morph around body parts.
The downside of the pack was that it became uncomfortable to use. By the end of 15 minutes, the area being iced was somewhat numb and had some irritation from the cold. Care should be taken to avoid cold burns when using this product; keep icing times to 10 minutes or less.
All of the packs we tested got cold enough to treat inflammation (a drop in tissue temperature from 5 to 15°C). However, there were other practical reasons we didn’t select each as the top pick.
The Chattanooga Colpac polyurethane gel pack ($15) is more or less the same price as many other cold packs, but it is easily reusable, returning to its initial temperature in just under an hour. At $15 for the rectangular pack we tested, the price is less than most of the suite of packs available from Paradice. But the reason we didn’t pick this one is there was no compression built in—you’d have to buy an Ace bandage or something similar if you wanted to adhere to the PRICE treatment plan.
The Chattanoooga vinyl Colpac ($18) was not as insulated as its polyurethane counterpart, and it lost a significant portion of its coldness when simply exposed to room temperature. The pack also had some rough edges that could poke you, even when inside a microfiber towel. The vinyl pack took about the same amount of time to refreeze as the polyurethane pack. If you have your mind set on the Chattanooga gel packs, we feel that the polyurethane has a slight advantage over its vinyl counterpart, given it holds its temperature better and is slightly more comfortable to use. If you’re comparing otherwise identical products from other manufacturers, you might opt for a poly cover over a vinyl one—it just seems to perform marginally better at holding in the cold.
The Dynarex Instant cold packs ($17 for a case of 24 packs) work well for sudden injuries when you don’t have a frozen pack on hand. Because they are made for one time use, you’ll have to keep buying more over time, so they’re not ideal. However, an instant cold pack can be a great addition to an emergency or first aid kit.
The Arctic Ease ($14) wrap is a great concept: it doesn’t need to be cooled in the freezer, and the wrap needs a splash of water to rehydrate itself. The wrap works at room temperature by drawing heat out of the injured area. In between uses, you can throw it in a gym bag and it’ll be ready whenever you need it. The wrap works nicely the first few times it’s used. However, after repeated use, the wrap starts to stick to itself, making it difficult to re-wrap the injured area. The pack brought the skin temperature down by 5 to 7°C, within the lower limit of therapeutic temperature.
The Kold-Rite ($18) wrap is very similar in concept to the Arctic Ease, only it is typically stored in the refrigerator. Because it’s prechilled, the wrap was effective at lowering the tissue temperature by 10 to 13°C, but it was very fragile. After about five tests, the wrap started to tear in multiple places, so we disregarded it from further testing.
Thermipaq Icy Cold pack ($14) did not stay as well insulated as its Hot/Cold counterpart, so we did not include it in the second round of testing. Although we did not research or test the hot capabilities of pack, the Thermipaq Hot/Cold seems like a more flexible choice if your doctor has prescribed warm therapy for an injury.
The Mueller large ice bag ($7) is a well-insulated cold pack, but unfortunately, it just doesn’t have the same flexibility as the other packs. First, it can be difficult to mold it around the body if you are using large ice cubes. It’s better to use crushed ice if possible. Also, you must always have enough ice on hand to use this product; you can’t just grab a frozen, reusable ice pack out of your freezer when you need it, so it can be somewhat of a hassle.
The Aqua Calida small ice bag ($6) took about 10 minutes to get cold once filled with ice, which is why we excluded it from further testing. During testing at room temperature, instead of getting warmer with time, the pack continued to get cold over the first 10 minutes or so.
The Theramed backpad ($27) is just that—a back pad. Though it is well insulated and gets quite cold, it is difficult to use on other parts of the body, especially the ankle and other joints where the pack needs to be able to be molded around the injured area. It was also one of the most expensive packs we tested.
Wrapping it up
After injury, remember PRICE: protect, rest, ice, compress, and elevate. The Paradice Ice Pack takes care of the I and C better than anything else we tested. The compression cuff’s liquid-filled spheres effectively cooled the body to reduce inflammation while staying extremely comfortable against the skin. We recommend keeping at least one on hand for minor bumps and bruises.