Ice v’s Heat – when to use them by Mika Ireste

Knowing when to apply ice on an injury and when to apply heat can be confusing. In this article, Mika explains their application

Application of Heat and Ice

Ice and heat have been used for years by athletes to ease aches and promote recovery, but a lot of the time people will have different ideas on which should be used, when, for how long, and whether or not you should use them at all.

Ice therapy, also known as cryotherapy, is traditionally used for relief from swelling, seen where any tissue structure is suffering from an inflammatory reaction. The way ice therapy works is by bringing down the temperature of the affected soft tissues, causing a decrease in blood flow to the area. This is a simple way of helping to decrease inflammation, though not stopping the immune response altogether.

It’s advised that ice should be applied to the injured area as soon after the injury as possible. Ice is best used in the first phase of the healing process, known as the inflammatory phase. The inflammatory phase protects the injured area from further injury. The application of ice will help to reduce the swelling and therefore reduce pain. Heat should not be used in this first phase of healing as it has the opposite effect of ice and would increase swelling rather than reduce it.

The inflammation phase usually has a duration of two to three days post injury, so it is only after this that heat can be used to aid the healing process. If you’re not sure if you have the kind of injury that would benefit from ice, i.e. one that results in swelling caused by trauma to the muscle tissue, a good way to tell is if it is sensitive to the touch, feels hot, or you see a reddening of the skin.

There have been questions over the application of ice during the inflammatory phase, with some arguing that inflammation is a natural immune reaction and therefore should not to be interfered with. However, a natural response doesn’t always mean that we cannot benefit from controlling or treating it in some way.

So, if you’re going to use ice, how long do you apply it for? For a while the guideline seemed to be that you can apply ice for up to 20 minutes every two to three hours (while you are awake) in the inflammatory phase. Any longer than 20 minutes and the skin may become damaged and it could even lead to frostbite. However, there is an ongoing debate about how long it should be applied for and some current research suggests that ice should only be applied for up to ten minutes every two hours. This is because after ten minutes a reflex reaction occurs causing the veins to dilate again and allow blood to rush into the area causing more swelling, just what you were trying to avoid. An application time of somewhere in the middle (15 mins) will ensure the ice application has time to elicit an effect, without causing damage to the skin.

In all instances ice must be used safely and not directly onto the skin, always wrap packs in a cloth or towel before applying it. After the inflammatory phase you can also start to bring heat application into the healing process.

Applying heat to the body increases the temperature of the soft tissue and skin, bringing more blood into the area. This brings more oxygen into the damaged area thereby accelerating the healing. The increased blood flow will also bring additional nutrients essential for the healing process, and help to push out any toxins that have built up in the area. Heat modalities can be applied when the inflammation has reduced.

Much of what has been covered so far has made reference to the application of ice and heat during the healing phases post injury, but heat is not only for use after ice has done its job, it can also be applied to ease stiffness and aches in non-inflammatory injuries. Heat has been found to be helpful for many situations such as that all over body ache resulting form over exertion, stiffness relating to trigger points or muscle knots, osteoarthritis, fibromyalgia, cramping, sleep deprivation, vitamin D deficiency and rheumatic diseases. That list is not comprehensive but just an example of the kinds of situations in which heat can ease the discomfort caused.

Guidelines on how long you should apply heat are much more vague than those about the application of ice. It is primarily dependent on each individual and the comfort it brings them. Some minor aches may benefit from 15 minutes to half an hour, others may apply heat for anything from half an hour to two hours, or even longer. The importance here is that it is applied safely. Get a towel between the skin and the hot water bottle and read the instructions on your heat packs and gels! Heat does not have to be hot, warmth can be enough.

Ice and heat therapy can be used for the whole body, not just locally. Ice baths are very popular with endurance athletes and it is advised that immersion into the ice baths should start with one minute only progressing slowly to ten minutes one minute a week to allow your body to adjust. For heat the same applies as for local application, the importance is that it is not too hot to burn you, a warm Jacuzzi, bath or sauna can be beneficial for varying lengths depending on your needs.

Heat and ice have varying benefits for everyone, and debates and studies will go on for some time into their efficiency. Just remember to use them safely and not rely on them for a magical cure!