Heating pads. Cold packs. Icy plunges. There’s no shortage of modalities for hot and cold therapies. But when are the right times to use them, and when should you stop DIY efforts and get specialized care?
Heat is a vasodilator, which means it increases blood flow. Heat helps once the acute phase of an injury has passed as well as when you want relief from chronic or longstanding aches and pains.
It can help remove toxins, relax muscles, and help loosen connective tissue. That’s how it eases stiffness, boosts healing and, in turn, lessens discomfort. Cold is a vasoconstrictor, meaning it reduces blood flow. In general, cold therapy works best for acute injuries, like a sudden strain or sprain, and flares of inflammatory conditions like bursitis. If you have a swollen ankle, for example, applying cold can reduce swelling and lessen pain.
At-home heat therapy options deliver superficial heat, penetrating less than 1 centimeter (cm) deep. Deep heat treatment, which can reach between 3 and 5 cm, is typically administered by a physical therapist or another orthopedic professional. Heat treatments can be dry, like a sauna, or moist, like a steam room or a simple soak in a hot bath (or a hot tub). You may find you respond better to one than the other.
Heating pads and sleeves. This heat-delivering mainstay has benefited from many advances, including gel technology. Many styles are made to envelop a joint—you wrap it over the area like a towel. There are also many different sizes available (some so large they will cover your entire back) as well as shaped “sleeves” for arms and legs. Some pads have settings for dry heat, moist heat, and even cold for ice therapy.
In a pinch, you can dampen a towel, zap it in the microwave for a few seconds to heat it up, and then place over the achy area—note that the towel shouldn’t be too hot to handle.
Timing: 20 minutes on, repeat hourly as needed.
Paraffin baths. Formerly available only in spas or nail salons, these small units can improve circulation in hands, feet, and elbows. The tub holds a special wax that melts and reaches between 125 to 129°F. By quickly and repeatedly (about 10 times) dipping your extremity in the wax, you create a warming glove that penetrates to the small muscles and then peels off. For other parts of the body, like a hip or thigh, you can use a brush to layer on the wax.
Timing: Wait 30 minutes before peeling off the wax. It’s great to follow this up with any muscle exercises you’ve been given to improve function.
Saunas, steam rooms, and hot tubs. If you have access to these facilities, you may find them very soothing.
Timing: 20 minutes. Set a timer if there’s any risk of your falling asleep.
Deep heat modalities. A number of modes of deep heat, including ultrasound, microwave, and diathermy radio and sound waves, are available to health-care professionals. The most commonly used is ultrasound, similar to a diagnostic ultrasound. A gel is swabbed over the area to be treated and then a soundhead rolls over it, usually in a continuous mode over soft tissue and in a pulsed mode over bony areas. Ultrasound also encourages healing, so it may be part of your recovery plan after an injury.
Timing: 5 to 10 minutes on each area, administered by a licensed health-care professional.
Weighted wraps. Similar to the effects of a weighted blanket, a weighted wrap may offer some relief from the anxiety that can accompany pain. Some wraps are shaped for specific problem areas like the neck and shoulders or lower back. They may have a dual function so they can be heated in a microwave or chilled in the freezer.
Timing: 20 minutes on, repeat hourly as needed.
Forms of cold therapy run the gamut from a simple ice pack to cryogenic chambers cooled to hundreds of degrees below zero.
Topicals. These include sprays, gels, creams, and sticks that cool skin on contact. Some are made with botanicals like peppermint or its extract menthol, while others are formulated with chemicals, sometimes with an anesthetic like lidocaine. Sprays are popular, especially with runners, because they’re easy to carry and use. It only takes a second to spray a problem area like the Achilles tendon or iliotibial band, the network of fibers that runs from the outer hip down the thigh to the tibia.
Timing: These products work instantly, but it helps to follow up a spray with very gentle stretches, especially if you’re working through a contraction or spasm. Hold each stretch for 30 to 60 seconds if you can. Important: If your skin develops a local irritation to any topical product, stop using it.
Cold packs and wraps. These include single-use chemical packs that are activated when you snap or break them (good for on-the-go) and reusable options you store in the freezer. The reusables have come a long way from rigid rectangles. Some pads or wraps are so thin that they’ll conform to any part of the body, even when frozen. Some come with Velcro straps to hold the pad in place. In a pinch, a bag of frozen vegetables like corn kernels or peas can mimic the effect of a cold wrap and can be reused (just place a thin towel between your skin and the bag, and label the bag so no one eats them by mistake.)
Some heating pads now offer a cold therapy setting, giving you cold and hot options in one product.
Timing: 20 minutes on, repeat hourly as needed.
Ice cup. Fill a small paper cup with water and freeze it, then give yourself an ice massage, making circles with the ice and peeling off the paper as you go.
Timing: 7 to 10 minutes, repeat hourly as needed. This is the only type of ice application where you don’t need a towel between your skin and the ice.
Ice baths. You might have seen photos of athletes submerged in tubs filled with ice water as part of their post-game routine. You can replicate this at home by taking the plunge in your own bathtub filled with cold water and ice cubes.
At some spas, you can use a strategy that has been popular in Scandinavian countries for centuries: plunging into a cold pool before entering a sauna or hot tub. It has the effect of pumping blood supply for enhanced circulation.
Timing: 30 seconds to 10 minutes, depending on what you can tolerate.
Cold-compression sleeves and wraps. These are typically used in a clinic or hospital after a severe injury or a procedure like rotator cuff surgery. Cold water runs through a wearable device that also provides compression. Home versions are available, but their use should be guided by a physical therapist or other licensed health-care professional.
Cryotherapy chambers. Available at specialized clinics, these are extremely cold environments that you sit in (as you would a sauna), but only for a few minutes at a time.
Timing: As indicated by your PT.
Some health conditions make using hot, cold or both dangerous. If you’re being treated for a serious illness, such as cancer, get clearance from your doctor. Here are general guidelines:
Don’t use hot or cold if you:
Don’t use cold if you:
Don’t use heat if you:
Don’t use deep heat if you:
