Open Accessibility Menu

When to use ice or heat in an injury

  • Posted On:
  • Written By: Brittany Johnson, DPT
When to use ice or heat in an injury

The age old question, should I use ice or heat? The answer: It depends!

Both ice and heat are appropriate, but factors such as the timing of the injury and the amount of swelling are factors that will help you make your decision.

Physical therapists, occupational therapists and other health care professionals will use ice and heat—or instruct you to use ice and heat—to manipulate blood flow to different areas of the body in order to promote the best healing.

As a general rule of thumb:

  • for acute/subacute injuries or recent surgeries (within the last seven to 14 days), apply ice treatments for 20 minutes of every hour that you are able, to reduce swelling and manage pain.
  • for chronic injuries/pain (longer than two to three weeks) use moderate heat for no more than 20 minutes at time.
  • for reoccurring injuries or “flare ups”, use ice for the initial flare up treating it as an acute injury and return to using heat after approximately two weeks.

Let’s look at this for an example! 

Have you ever sprained your ankle? You’ve likely noticed that it becomes swollen, bruised and painful very quickly. Use ice on it and see the swelling and bruising go down, at least temporarily. When you suffer from an injury – or flare up - that occurs suddenly, your body goes into an inflammatory process, in which there is an immediate increase in swelling. Swelling is not always bad and is important for healing the damaged tissue. Swelling is your body’s response to direct blood (which contains the necessary ingredients for healing) to the injured area. However, if there is too much swelling, then new healthy blood cannot get to the damaged tissue. When we apply ice, vasoconstriction occurs —this is the shrinking of the blood vessels. Vasoconstriction forces the swelling, fluid, and blood out of the area and allows for new blood to come in. Often times, this is why the initial reduction in swelling is temporary, because as we push old swelling out, new blood comes in for healing and increases swelling again. It is very important to utilize ice in order to help your body cycle old swelling with new healing blood to promote the best chance for healing.

On the other hand, heat is used to increase blood flow to the area after your body is no longer using it’s natural swelling response, but you still have pain. This is helpful for more chronic pains or from an injury that occurred more than a couple weeks ago. The use of heat increases blood flow, to continue to promote healing, help muscles relax and loosen tissues before or after participating in daily activities. Do not use heat after an acute injury, recent surgery or after any significant increase in activity such as a sporting event. When using a heating pad, rice pack or a hot wet towel, never leave them on for extended periods of time or while sleeping in order to avoid burns.

If you have any questions about what is the best option for your particular injury or aches and pains, contact your physical or occupational therapist and they will be happy to help.

Brittany Johnson, PT, DPT, practices at Campbell County Health Rehabilitation Services in Gillette, Wyoming, which provides complete physical and occupational rehabilitation care to people with musculoskeletal problems caused by disease or injury. Our compassionate and experienced staff strives to help you reach your rehabilitation goals and function at your optimal level, whether you are at home or at work. Learn more at

  • Category: Campbell County Medical Group Walk-In Clinic & Occupational Health, Emergency Department, Surgery, Wellness, Rehabilitation Services