Ice and heat are both effective therapies for injuries, but the type of injury you have will determine when you should ice and when you should use heat.

In general, acute injuries, which happen suddenly, usually need ice to reduce inflammation. Chronic (long-term) pain benefits from heat to relax tissues and stimulate blood flow. However, there are certain cases where chronic pain can also benefit from ice, such as after physical activity.

This article will explain how to decide when to use ice and heat (or both) for an injury. 

Ice Treatment

Ice treatment is most commonly used for acute injuries to reduce swelling, pain, and inflammation.

Inflammation is the body’s natural response to an injury or infection. Blood vessels and tissues swell so immune cells can get closer to the damage. While important for healing, inflammation that is not controlled can cause extreme pain and disability.

If you have had a physical injury in the past 48 hours, an ice pack can help minimize swelling, reduce bleeding within tissues, as well as help relieve muscle spasms and pain.

Ice treatments can also be used to treat chronic conditions, including overuse injuries in athletes (such as tendinitis, tendinosis, or bursitis). The pack is applied immediately after physical activity to proactively treat inflammation.

How to Safely Ice an Injury

You can buy freezable gel ice packs at the pharmacy or online. You can also make a pack with ice cubes put into a plastic bag or wrapped in a tea towel. A pack of frozen peas is another option.

Arthritis, migraine headaches, and trigeminal neuralgia are examples of chronic disorders that may benefit from ice application.

To safely ice an injury:

  • Never place ice directly on the skin. Always use a cloth barrier like a thin bath towel between the ice and the injured area.
  • Keep the ice pack moving to prevent frostbite. Never keep the pack in one place for more than a couple of minutes at a time.
  • Never ice an injury for more than 15 to 20 minutes. It is better to ice an injury several times a day than all at once.
  • Remove the pack if you feel prickly pain or the skin starts to look bright pink or red.
  • Do not use an ice pack on the left shoulder if you have a heart condition.

Heat Treatment

Heat treatment is used to treat chronic conditions. The heat helps relax tissues and stimulates blood flow to the affected joint or muscle. Heat is typically used to treat overuse injuries before an action is performed.

Heat can also relieve pain caused by muscle tension. Heating can help relax tissues and loosen stiff joints, making it a useful treatment for musculoskeletal conditions such as arthritis and old muscle strains.

Steamed towels or moist heating pads help the heat go deep into the muscles. Some people find that moist heat provides better pain relief than dry heat.

How to Safely Heat an Injury

Heat application can be done with an electric heating pad or even a warmed-up towel just taken out of the dryer. If you’re using an electric pad, pick one with temperature control to prevent overheating and burns.

There are also microwaveable bags filled with wheat, rice, or other natural or synthetic ingredients that can be used for heat therapy. However, they are not necessarily safer than electric heating pads because they can cause burns if overheated. Plus, wheat bags have been known to catch fire in the microwave.

To use heat application safely:

  • Do not use heat treatments after activity.Do not use heat to treat an acute injury.Always use moderate heat (the temperature should never cause sweating or discomfort).Do not heat a towel with boiling or scalding water.Never use heat on an area with swelling.Never use heat on broken or damaged skin.Never use heat for extended periods of time or while sleeping.

Summary

If you have an acute injury, ice can help reduce pain and swelling. With chronic conditions, using ice after an activity can help control inflammation. To safely ice an injury, always use a cloth barrier between your skin and the ice. Never ice an injury for more than 15 to 20 minutes.

Heat therapy will be helpful later in your recovery or if you have chronic pain. Using heat before an activity will help losen muscles and joints. Use moderate heat and never apply for extended periods or while sleeping.

  • Malanga GA, Yan N, Stark J. Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgrad Med. 2015;127(1):57-65. doi:10.1080/00325481.2015.992719
  • Malanga GA, Yan N, Stark J. Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgrad Med. 2015;127(1):57-65. doi:10.1080/00325481.2015.992719

By Jonathan Cluett, MD

Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men’s and women’s national soccer teams.