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Overview
We treat everything from arthritis to pulled muscles to inflammation with ice packs or heating pads. Treating pain with hot and cold can be extremely effective for a number of different conditions and injuries, and easily affordable. The tricky part is knowing what situations calls for hot, and which calls for cold. Sometimes a single treatment will even include both.
As a general rule of thumb, use ice for acute injuries or pain, along with inflammation and swelling. Use heat for muscle pain or stiffness.
Heat therapy works by improving circulation and blood flow to a particular area due to increased temperature. Increasing the temperature of the afflicted area even slightly can soothe discomfort and increase muscle flexibility. Heat therapy can relax and soothe muscles and heal damaged tissue.
Types
There are two different types of heat therapy: dry heat and moist heat. Both types of heat therapy should aim for “warm” as the ideal temperature instead of “hot.”
- Dry heat (or “conducted heat therapy”) includes sources like heating pads, dry heating packs, and even saunas. This heat is easy to apply.
- Moist heat (or “convection heat”) includes sources like steamed towels, moist heating packs, or hot baths. Moist heat may be slightly more effective as well as require less application time for the same results.
Professional heat therapy treatments can also be applied. Heat from an ultrasound, for example, can be used to help pain in tendonitis.
When applying heat therapy, you can choose to use local, regional, or whole body treatment. Local therapy is best for small areas of pain, like one stiff muscle. You could use small heated gel packs or a hot water bottle if you only want to treat an injury locally. Regional treatment is best for more widespread pain or stiffness, and could be achieved with a steamed towel, large heating pad, or heat wraps. Full body treatment would include options like saunas or a hot bath.
When not to use
There are certain cases where heat therapy should not be used. If the area in question is either bruised or swollen (or both), it may be better to use cold therapy. Heat therapy also shouldn’t be applied to an area with an open wound.
People with certain pre-existing conditions should not use heat therapy due to higher risk of burns or complications due to heat application. These conditions include:
If you have either heart disease or hypertension, ask your doctor before using heat therapy. If you are pregnant, check with your doctor before using saunas or hot tubs.
Heat therapy is often most beneficial when used for a good amount of time, unlike cold therapy, which needs to be limited.
Minor stiffness or tension can often be relieved with only 15 to 20 minutes of heat therapy.
Moderate to severe pain can benefit from longer sessions of heat therapy like warm bath, lasting between 30 minutes and two hours.
Cold therapy is also known as cryotherapy. It works by reducing blood flow to a particular area, which can significantly reduce inflammation and swelling that causes pain, especially around a joint or a tendon. It can temporarily reduce nerve activity, which can also relieve pain.
Types
There are a number of different ways to apply cold therapy to an affected area. Treatment options include:
- ice packs or frozen gel packs
- coolant sprays
- ice massage
- ice baths
Other types of cold therapy that are sometimes used include:
- cryostretching, which uses cold to reduce muscle spasms during stretching
- cryokinetics, which combines cold treatment and active exercise and can useful for ligament sprains
- whole-body cold therapy chambers
When not to use
People with sensory disorders that prevent them from feeling certain sensations should not use cold therapy at home because they may not be able to feel if damage is being done. This includes diabetes, which can result in nerve damage and lessened sensitivity.
You should not use cold therapy on stiff muscles or joints.
Cold therapy should not be used if you have poor circulation.
For home treatment, apply an ice pack wrapped in a towel or ice bath to the affected area. You should never apply a frozen item directly to the skin, as it can cause damage to the skin and tissues. Apply cold treatment as soon as possible after an injury.
Use cold therapy for short periods of time, several times a day. Ten to 15 minutes is fine, and no more than 20 minutes of cold therapy should be used at a time to prevent nerve, tissue, and skin damage. You can elevate the affected area for best results.
Heat therapy should utilize “warm” temperatures instead of “hot” ones. If you use heat that’s too hot, you can burn the skin. If you have an infection and use heat therapy, there is a chance that the heat therapy could increase the risk of the infection spreading. Heat applied directly to a local area, like with heating packs, should not be used for more than 20 minutes at a time.
If you experience increased swelling, stop the treatment immediately.
If heat therapy hasn’t helped lessen any pain or discomfort after a week, or the pain increases within a few days, make an appointment to see your doctor.
Risks of cold therapy
If you’re not careful, cold therapy applied for too long or too directly can result in skin, tissue, or nerve damage.
If you have cardiovascular or heart disease, consult your doctor before using cold therapy.
If cold therapy hasn’t helped an injury or swelling within 48 hours, call your doctor.
Knowing when to use cold therapy and when to use heat therapy will significantly increase the effectiveness of the treatment. Some situations will require both. Arthritic patients, for example, may use heat for joint stiffness and cold for swelling and acute pain.
If either treatment makes the pain or discomfort worse, stop it immediately. If the treatment hasn’t helped much with regular use in a few days, you can make an appointment to see your doctor to discuss other treatment options.
It’s also important to call your doctor if you develop any bruising or skin changes over the course of treatment.
When you injure yourself, you may reach for a hot or a cold pack. Which option is better depends on the nature of your pain, what caused it and how long you’ve had it.
Heat therapy, sometimes called thermotherapy, involves applying heat to an injury or painful area on the body. Hot water bottles or pads that can be heated in a microwave oven are commonly used. Cold therapy, or cryotherapy, can come in the form of water bottles or pads cooled in a fridge or freezer.
Placing something cold at the injury site causes the blood vessels, arteries and veins, to narrow. This reduces blood flow through the area and helps reduce inflammation and swelling. Adding heat to the area has the opposite effect: opening the blood vessels up and increasing blood flow through injured tissue.
These opposite effects are useful in different situations.
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Cooling down to prevent inflammation
We can treat injury or tissue pain with a hot or cold pack, or sometimes alternate the two.
Cold therapy should be used for injuries that result in swelling and inflammation such as joint sprains, muscle strains or bruises. The objective is to slow blood flow to the area and prevent the effects of the injury. Gel packs that can be kept in the freezer, coolant sprays or even a bag of frozen veggies will do the job.
It is important to avoid holding ice in direct contact with the skin for long periods as this can cause skin damage. It is best to wrap ice in a cloth and then apply it.
Cold therapy is most effective in the immediate or acute phase of pain when swelling and inflammation first kicks off. Typically, the treatment should be applied for about 20 minutes and can be reapplied every two hours for a few days. After that, the injury should be well into the healing phase and the swelling and inflammation will subside.
Cold therapy, or applying ice, is often used in conjunction with rest, compression and elevation, known in first aid by the acronym RICE.
So, ice can be useful when we want to limit the initial swelling and pain, since too much or prolonged swelling can impede the healing process. But with less severe injuries like minor sprains and strains, inflammation is part of the body’s healing process and continuing cold therapy can be a barrier to recovery.
When to warm up
Heat therapy is generally thought of as being either dry or moist.
Dry heat therapy includes hot water bottles or heated pads. These are easy to apply and are effective for reducing pain. Moist heat therapy includes warm bath, hot wet towel and moist heat packs.
Heat therapy is not recommended for acute management of sprains, strains or contusions as this promotes blood flow and can increase swelling and pain.
Heat therapy can help chronic conditions such as recurring joint pain, neck or back pain.
If pain is due to a strain or sprain, cold therapy should be applied immediately, but heat therapy can help relieve pain from 72 hours post-injury.
Heat therapy does not mean applying something very hot, rather it should be warm, pleasant and easily tolerated for long periods.
Heat therapy can be very effective for muscle tension or joint stiffness — increasingly blood flow and heating muscles or joints for around 15 minutes before physical activity as a kind of warm up. This approach can also help people engage in activities that might aggravate a chronic injury by loosening and relaxing injured muscles.
Heat is used differently for bluebottle stings. These are best treated by a medical professional in a hospital emergency department. But, as a first aid intervention, pain can be reduced by applying hot water (42–45°C) to the area for 30–90 minutes.
Alternating hot and cold to an area of pain has been used for decades but there has not been a great deal of research assessing the practice. One study assessed hospital inpatients with heel pain and found greater improvement in foot function after hot/cold therapy compared with a group who underwent standard therapy.
Soaking in it
Athletes commonly use water immersion therapy for recovery.
However, this practice is also not without controversy. One review of the evidence found cold water immersion improved performance, measured by jumping and all-out sprint ability 24 hours after a sporting event. Fatigue was also reduced at 48–72 hours after sports events.
This type of temperature control therapy may also help with recovery after undertaking some sustained physical exertion such as a day of hiking.
So, cold first and maybe heat later
The take-home message is that cold packs work well for reducing pain and inflammation in the acute phase of a strain, sprain or bruise — especially when used in as part of the RICE method.
Heat packs are useful for reducing muscle tension and stiffness and pain in the joints, but never in the initial phase of an injury. There is not enough evidence to show alternating the two is particularly useful, while cold water immersion therapy may help recovery after sport or sustained physical exertion.
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