Heat or Cold – What’s best to use when?
May 26, 2019
As physiotherapists we often get asked whether the application of heat packs or ice packs is more useful for all sorts of injuries. The answer isn’t black and white. It depends on your injury, what stage of healing you’re up to and what your preferences are. Typically, an acute (fresh or new) injury will respond better to icing and a chronic (older or persistent) injury will like heat. However, there are exceptions and the effectiveness of both is up for debate.
What does heat do?
Physiological effects of heat therapy include pain relief, increases in blood flow, metabolism and elasticity of connective tissue. Increasing blood flow and metabolism is thought to promote healing by increasing the supply of nutrients and oxygen to the site of injury. Increased elasticity can lead to improvements in range of motion.
When should I use heat and how do I do it?
Heat therapy is good for muscle spasm, joint pain and chronic pains. Heat should be avoided when inflammation is present as it can make it significantly worse. It is good for back pain, osteoarthritis and general muscle soreness. Heat can be applied via a heat pack, hot water bottle or via hot water such as a bath or shower. Heat should not be applied to an infection, acute injuries or flare ups of arthritic joints. It is best applied as a comfortable even warmth for some 20-30 minutes and can be applied whenever you are able.
What does cold do?
Cold therapy decreases blood flow which is thought to reduce swelling and slow the delivery of inflammatory mediators, reducing inflammation of the affected area. Interestingly, this is most effective when combined with elevation and compression. Most importantly, it induces a local anaesthetic effect by decreasing the activation of nociceptors and the conduction velocity of nerve signals conveying pain.
When should I use cold and how?
Cold therapy is best used for acute injuries. Back pain generally prefers heat rather than cold and is an exception to this rule. It is best applied with an ice pack, frozen peas or massaging with an ice cube. If using an ice pack or frozen vegetables it is best to wrap in a moist towel and apply for 20 minutes at a time every 2 hours. If massaging directly with ice, rub your skin for a few minutes or until the area becomes numb. Cold therapy should not be used in patients with cold hypersensitivity, cold intolerance, or Raynaud’s disease, or over areas of vascular compromise.
Heat and cold therapy will not have a huge effect on your recovery from an injury, though they do have a recognized effect for decreasing pain. A reduction in pain can, however, allow you to start moving earlier which is important for all injuries. If you are torn between using cold or heat, try them both and see which you prefer. Use whatever feels the best to you.
Should you need a hot or cold pack please pop in. We have varying options readily available for your immediate relief.
Written by: Lachlan Oberg
Moody, J. Heat Vs Cold Therapy- Which One Should I Use? https://www.physioinq.com.au/blog/cold-vs-heat. 2016
Ingraham, P. The Great Ice Vs Heat Confusion Debacle. https://www.painscience.com/articles/ice-heat-confusion.php. 2017
Ingraham, P. Heat for Pain. https://www.painscience.com/articles/heating.php. 2016
Ingraham, P. Icing For Injuries, Tendonitis, and Inflammation- Become a Cryotherapy Master. https://www.painscience.com/articles/icing.php. 2017
Gerard A. Malanga, Ning Yan & Jill Stark (2015) Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury, Postgraduate Medicine, 127:1, 57-65, DOI: 10.1080/00325481.2015.992719