When to Use Ice or Hot?

Are you confused about when to use Heat and when to use Cold?

Knowing when to use hot therapy vs. cold therapy is very important to healing because they have opposite reactions in the body.  Using the wrong one can inflame and aggravate an injury, while using the correct one can greatly aid in your treatment.

Heat treatment and ice treatment have opposite reactions.  Heat is relaxing to muscles, but it will increase swelling and inflammation (such as the inflammation associated with tendonitis.)  Ice shrinks the swelling and inflammation, but it will further tighten up a muscle spasm.  Making things worse is that many areas of the body the muscles overlap with the tendons.  So which one should you use?

The answer is different for different conditions and different area of the body.

Both heat and ice improve healing by manipulating blood flow, reducing inflammation, and reducing pain. Knowing which one to use when will keep you from possibly doing further damage.

What is an overuse injury?
Overuse syndromes, also called cumulative trauma disorder (CTD) or repetitive strain injury (RSI), are conditions characterized by chronic irritation to a body part.

Acute and Chronic Pain

There are two basic types of athletic injuries: acute and chronic.

Acute Pain is of rapid onset and short-lived, or

Chronic Pain develops slowly and is persistent and long-lasting.

Acute and Chronic Injuries

Acute injuries are sudden, sharp, traumatic injuries that occur immediately (or within hours) and cause pain (possibly severe pain). Most often acute injuries result from some sort of impact or trauma such as a fall, sprain, or collision and it’s pretty obvious what caused the injury.

Acute injuries also cause common signs and symptoms of injury such as pain, tenderness, redness, skin that is warm to the touch, swelling and inflammation. If you have swelling, you have an acute injury.

Chronic injuries can be subtle and slow to develop. They sometimes come and go, and may cause dull pain or soreness. They are often the result of overuse, but sometimes develop when an acute injury is not properly treated and doesn’t heal. Cold therapy with ice is the best immediate treatment for acute injuries because it reduces swelling and pain. Ice is a vaso-constrictor (it causes the blood vessels to narrow) and it limits internal bleeding at the injury site. Apply ice (wrapped in a thin towel for comfort) to the affected area for 10 to 15 minutes at a time. Allow the skin temperature to return to normal before icing a second or third time. You can ice an acute injury several times a day for up to three days.

So which one is the right one to use for your injury, ice or heat?  And how long should the ice or heat treatments last?

When to treat with ICE

Cold therapy (or cryotherapy) is the treatment of choice for acute injuries (injuries that have occurred within the last 72 hours).

With any sprain, strain or bruise there is some bleeding into the underlying tissues. This may cause swelling, pain and delay healing. During immediate treatment, the aim is to limit the body’s response to the injury.   It does this by reducing further bleeding into the injured tissues, preventing or reducing swelling, and reducing muscle spasm and pain. Ice reduces pain by numbing the area and by limiting the effect of swelling which causes pain.

When applied immediately after an injury, cold treatment reduces tissue damage by reducing the metabolic rate and decreasing the production of metabolites and metabolic heat which result from the body’s inflammatory response to the injury.

Cold therapy relieves muscle spasms, reduces post-exercise soreness, and stimulates circulation in areas of chronic discomfort.

Ice treatment may be used in both the immediate treatment of soft tissue injuries and in later rehabilitation.

Ice packs are often used after injuries such as an ankle sprain have occurred. Applying an ice pack early and often for the first 48 hours will help minimize swelling. These effects all help to prevent the area from becoming stiff by reducing excess tissue fluid that gathers as a result of injury and inflammation.

In the later, or rehabilitation, phase of recovery the aims change to restoring normal function. At this stage the effects of ice can enhance other treatments such as exercise by reducing pain and muscle spasm. This then allows better movement. If you have to do exercises as part of your treatment it can be useful to do them with ice in place or immediately after it is removed when the area will still be a little numb. This reduces pain and makes movement around the injury more comfortable.

Ice treatments should also be used for chronic conditions (arthritis, tendonitis, and overuse injuries in athletes); ice the injured area after activity. This will help control the inflammatory response. Never ice a chronic injury before activity. Cold therapy can be applied with ice packs, cold and ice whirlpools, ice massage, commercial cold sprays


There are several methods for icing an injury. The best way to ice an injury is with a high quality ice pack that conforms to the body part being iced. Place a thin layer of cloth over the injury, to avoid frostbite. Place the ice pack over the cloth. Leave the ice on for 20 minutes. It is normal to go through the phases of cold, burning, and then numbness. Do not leave the ice on for more than 20 minutes, or you can do more harm than good.

Ideally, rub a small amount of oil over the area where the ice pack is to go (any oil can be used, even cooking oil!). If the skin is broken or there are stitches in place, do not cover in oil but protect the area with a plastic bag. This will stop the wound getting wet.

  • Place a cold wet cloth over the oil (do not need if using plastic bag).
  • Place the ice pack over the cloth.
  • Check the color of the skin after 5 minutes. If it is bright pink/red remove the pack. If it is not pink replace the bag for a further 5-10 minutes.
  • Ice can be left on for 20 to 30 minutes but there is little benefit to be gained by leaving it on for longer. You run the risk of damaging the skin if ice is left on the skin for more than 20-30 minutes at a time.

The effect of the ice pack is thought to be improved if it is pressed gently onto the injured area. Ice can burn or cause frostbite if the skin is not protected with oil and/or other protection such as a wet cloth.

How long should ice be applied?

  • Treatment time varies depending on several factors, including the size of the treatment area, the type of cold therapy applied, and the size of the individual. For example, a thin person requires less treatment time because the cold does not need to penetrate through as much tissue to lower intramuscular temperatures. You’ll know when you’ve had the cold on long enough, by monitoring the four stages of cold treatment: The first stage is an uncomfortable feeling; the second stage is a stinging sensation; the third stage is burning or aching; the fourth stage is numbness. It takes five to fifteen minutes to reach all four stages.
  • Ice should be applied within 5-10 minutes of injury for 20-30 minutes
  • Repeat the cold application every 2-3 hours while awake for the first 24-48 hours after an injury.
  • To reduce post-exercise soreness, apply cold immediately after exercise for 10 to 20 minutes.
  • For chronic discomfort, apply cold for a minimum of 10 minutes. Repeat as necessary.

After the first 48 hours when bleeding should have stopped the aim of treatment changes from restricting bleeding and swelling to getting the tissues re-mobilized with exercise and stretching. Ice helps with pain relief and relaxation of muscle tissue.

Another method of icing is ice massage.  Freeze a paper or Styrofoam cup full of water, and then tear off the top rim to expose the ice. Move the ice continuously over the injury for 15 minutes.


  • If you suffer from “ice burn” or “ice allergy” when you are exposed to cold, wrap the cold pack with a damp towel.
  • Follow packaged instructions carefully. Ice can burn or damage tissues if used improperly.
  • You can damage skin by prolonged, direct contact with reusable ice packs. Always place a damp washcloth beneath the ice pack to prevent harm to the skin.

When not to use cold

  • Do not use over insensitive skin or in the presence of poor circulation.

Elderly people, young children, and people with diabetes must be very careful with cold treatments. If you have any questions about cold therapy, ask your health care practitioner for advice.

Do not use ice packs on the left shoulder if you have a heart condition. Do not use ice packs around the front or side of the neck.

How do you make ice packs?

Ice packs can be made from ice cubes in a plastic bag or wet towel.  A packet of frozen peas is also ideal. These mold nicely and can go in and out of the freezer.  Take care when using ice and cold packs from a deep freeze. These are very cold and can cause ice burns quickly if used without care and proper protection.

Homemade Cold Pack

Tip#1:  Mix one cup of alcohol with two cups of water, and seal it inside a zip-lock freezer bag.  You may want to double-seal the pack with a second zip-lock bag.  The alcohol keeps it from freezing completely, so it stays slushy for good ice pack consistency.   It lasts for 15 minutes or longer, and can be used over and over. It might get a little cold, so put a towel between the bag and your bare skin when you use it.  Clearly label the packet as a non-edible ice pack.  Rubbing alcohol is toxic when ingested.


Tip#2: Put some blue food coloring in there and it will look just like the ice packs you buy at the sporting goods store!


Tip #3: To make this one even easier, skip the water/alcohol mixture. Instead, fill the bag with dish washing soap (such as Dawn or Palmolive) double bag in plastic zip seal bags designed for freezer storage and place in the freezer for at least two hours; The dishwashing liquid will not solidify, but for an icy gel. It will conform to your body nicely; you can wrap this type of ice pack around knees or elbows and secure it in place with a cotton bandage.


Tip#4: Use rice to create a mild ice pack.  Insert 1 1/2 cups of rice into a sandwich sized, plastic zip seal bag. (Any type of rice will do.) Freeze the rice for two hours. The result is a simple ice pack that feels quite cool, yet not ice cold, to the skin. This is an excellent form of cold therapy for patients who find ice pack temperatures too uncomfortable to withstand. To make a larger version, use 4 cups of rice and a gallon-sized plastic bag.


Tip#5: Create a firm, custom-molded reusable ice pack by drenching a new disposable diaper with plain water. Fold and double bag the wet diaper, and then freeze it overnight. When it emerges, the ice pack will be stiff. Knead it well, and the gel granules inside the diaper will loosen enough to mold into a custom fit.


Tip #6: Boo-boo ice packs – use restaurant ketchup packs.  The ketchup won’t freeze solid and they’re small enough for little hands to hold easily (and they’re free).


When to treat with HEAT

Heat treatment (or thermotherapy) relieves stiffness and chronic aches, facilitates relaxation, and stimulates circulation. It works by increasing tissue temperatures and blood flow, thereby drawing extra nutrients into the area to assist in the recovery and healing process.

Heat Therapy
Heat treatments should be used for chronic injuries or injuries that have no inflammation or swelling. Heat applied to chronic conditions helps relax and loosen tissues, and to stimulated blood flow to the area.

When an injury is older than 48 hours, heat can be applied in the form of heat pads, deep heat cream, hot stones, hot water bottles or heat lamps. Heat causes the blood vessels to dilate (open wide) which brings more blood into the area. It also has a direct soothing effect and helps to relieve pain and spasm. If heat is applied to the skin it should not be hot, gentle warmth will suffice. If heat is applied there is the risk of burns and scalds. The skin must be checked at regular intervals. Ice often gives better and longer lasting effect on the circulation than heat. The pain killing properties of ice are also deeper and longer lasting than heat.

Sore, stiff, nagging muscle or joint pain is ideal for the use of heat therapy. Athletes with chronic pain or overuse injuries may use heat therapy before exercise to increase the elasticity of joint connective tissues and to stimulate blood flow. Heat can also help relax tight muscles or muscle spasms.

Don’t apply heat after exercise or after an acute injury.  It will increase bleeding and make the problem worse.  After a workout, ice is the better choice on a chronic injury.

Because heat increases circulation and raises skin temperature, you should not apply heat to acute injuries or injuries that show signs of inflammation. Safely apply heat to an injury 15 to 20 minutes at a time and use enough layers between your skin and the heating source to prevent burns.

How to Apply Heat

Moist hot towels are the most effective form of heat treatment. They are more effective because the moisture keeps the area from drying out and becoming brittle. Place a washcloth under hot tap water, or heat it up slightly in the microwave, and then apply it directly to the injured area. Heating pads will also work, as well as hot water bottles and soaking in a hot bath. Do not apply for more than 20 minutes at a time. Never fall asleep on a heating pad, and do not apply body weight to the heating pad (do not sit or lie on it.)

Heat can also be applied in other ways such as warm whirlpools, paraffin baths or infrared lamps or mats.  Never leave heating pads on for more than 20 minutes at a time or while sleeping.

Because some injuries can be serious, you should see your doctor if your injury does not improve (or gets worse) within 48 hours.

When not to use HEAT

  • Heat should never be used on acute injuries until the swelling is controlled. Heat draws fluids into tissues and can increase swelling and inflammation.  Do not use heat over swollen tissues or redness except under the supervision of your health care practitioner.
  • Do not use heat before vigorous exercise. Your muscles may be too relaxed for peak performance and safety.


Typical treatment times for heat applications are between fifteen and twenty minutes. It takes heat a minimum of fifteen minutes to penetrate tissues to reach therapeutic temperatures.

Moist heat penetrates more deeply than dry heat and will not dehydrate tissues so circulation is improved, speeding healing. For moist heat when using dry packs or warm gel packs, add a layer of moist toweling.


  • Follow packaged instructions carefully. Heat can burn and damage tissues if used improperly.
  • For steam heat, wrap hot packs in thick toweling to prevent scalding and control temperature. Use additional toweling as insulation if you lie on top of the hot pad.
  •  Do not use heat on a new injury (for example soaking in a hot bath, using heat lamps, hot water bottles, deep heat creams, etc.). These will increase bleeding and make the problem worse
  • Do not use heat over insensitive skin such as in areas where you have numbness or decreased skin sensation

Homemade Hot pack


Fill a cotton tube sock ¾ of the length with plain white rice, beans, flax seeds, cherry pits or oats, and sew or tie the end shut.  Heat this in the microwave on a pie plate (to keep it clean) for 2 minutes.  Be careful. It can catch fire if you cook it too long. The pack will be very hot at first, so wrap it in a washcloth before you place it on your skin.  As it cools, you can remove the washcloth.  It will stay warm for about 20 minutes.  You can use it over and over.  For a pleasant aroma, add some lavender or sage.

When to treat with both Hot and Cold (Contrast thermotherapy)

For chronic problems, alternate cold with heat applications for greater circulatory effect.

Combination Therapy 48-72 hours after an injury, you can also use combination therapy to get the most benefit from both heat and ice.  To do this, alternate hot and cold packs for 10 minutes each. By alternating, you keep the swelling under check with the ice, and keep blood and its nutrients circulating through the area with the heat. Be sure to always end with ice, so that the heat does not contribute to further swelling.

Precautions when using heat and ice

Do not use cold packs or heat over areas of skin that are in poor condition.

  • over areas of skin with poor sensation to heat or cold.
  • over areas of the body with known poor circulation.
  • if you have diabetes.
  • in the presence of infection.