Ice Vs Heat: when to use what…



Chances are you have used, or at least been told to use, ice or heat on an injury before.  Whether it involved grabbing a bag of frozen peas for a rolled ankle or having a hot bath to ease achy muscles it is likely to have (hopefully) provided some pain relief.  Both options are safe, effective and cheap methods of self care but how do we know when to use what?  And perhaps more importantly, how do we know when NOT to use ice or heat.  Keep reading to shed some light on the matter…


Ice is usually the first port of call for an injury.  Most of us are familiar with the acronym PRICE – protect, rest, ICE, compress and elevate.  This is a good reminder that ice is best used in the acute/fresh phase – up to 48 hours post injury.  Soft tissue injuries such as sprains (rolling an ankle or twisting a knee for example) or strains (pulling a muscle) result in the body initiating the inflammatory response.  This response involves an influx of fluid to the area, full of cells specifically designed to heal damaged tissue. This response, although a natural healing process by the body, leads to excess swelling, bruising and pain.  Ice can be utilized to reduce this.

The cold temperature acts as a vasoconstrictor, narrowing the blood vessels delivering blood to the damaged tissue, restricting the influx of fluid, which in turn, reduces the resultant swelling and bruising.  It also reduces pain by slowing the pain signals being sent to the brain and numbing the area.

Ice can also be beneficial for painful flare ups of chronic issues such as tennis elbow, golfers elbow, tendinitis, bursitis, plantar fasciitis and IT band friction syndrome for example.  As a general rule of thumb, if there is inflammation, use ice.  There are some cardinal signs of inflammation that make it easier to identify;

  • Swelling – around the injured tissue
  • Heat – the skin may feel warm to touch
  • Reduced function – pain may limit motion
  • Redness – the skin may be red along with warm
  • Pain

It must be noted that the use of ice has recently been debated and some research suggests it delays healing  (for more information click here and here).  Despite the arguments being made, ice is still widely used in the medical field and sporting industries as a cost effective, temporary pain reliever when used correctly, at the right time.

How to apply

Many different products are available to use; coolant sprays, freezable gel packs, cooling gels etc.  My personal fave is a good old bag of frozen peas to be honest!  Whatever you use make sure there is a protective layer between the ice and skin – such as a clean tea-towel, T-shirt or paper towel.  This will minimize risk of any irritation to the skin.  Always monitor the area for signs of irritation and be aware of the 4 phases of sensation;

  • Coldness
  • Burning
  • Aching
  • Numbness

Once the area feels numb, usually around 8-10 mins, remove the ice and allow the injured area to warm up naturally, 1 to 2 hours is usually sufficient.  Then repeat the process a few times throughout the day, up to 48 hours post injury.

When NOT to use ice

Anyone suffering from Raynauds Phenomenon, sensory loss to the area or cold hypersensitivity should avoid using ice.  Always consult your Dr if you are unsure though.

Its also not beneficial to use ice on old, chronic injuries and stiff muscles.  And definitely don’t use ice (or heat for that matter) on an open wound – it can greatly increase the risk of infection and we don’t want to slow down the natural healing process in these situations.



While ice is used to reduce pain and inflammation caused by acute injuries, heat is used in more chronic situations.  It can relax muscle tissue, decrease hypertonicity (fancy word for tension) and reduce the achy, dull pain often created by stiffness in joints and muscles.  It does this by acting as a vasodilator – widening the blood vessels of the tissue and improving circulation to the area. With improved circulation more oxygen and nutrients are carried to the injured area, promoting healing. It also has a neurological effect  – calming the nervous system and in turn, decreasing pain.
As it decreases muscle tension it can be particularly useful to apply heat prior to stretching or even before activity.

How to apply
Heat applications can come in various forms, perhaps with the most common being a hot water bottle or a microwavable bean bag.  In my treatments I use an electric, moist heat pad, all of which are readily available at the local pharmacy or online.  Whichever product you use be sure to follow the instructions to ensure safe use!

Always be careful with heat and keep checking the skin for what’s called ‘blanching’.  This is the blotchy red and white pattern that can appear on the skin after prolonged heat – ideally the heat should be removed before this occurs! Usually around 15 mins at a comfortably warm temperature should be sufficient.

When not to use heat

Due to the catalytic effect of heat, it is important NOT to use it when inflammation is present as it will speed up the metabolic activity of the cells and increase the swelling and bruising.  So never use heat for acute injuries!  Similar to ice, heat should also be avoided if there is any sensory impairment or an open wound.

Also consult your Dr if you suffer from hypertension or cardiac conditions as heat can alter circulation which may not be beneficial with these conditions.

To cut a long story short

Ice is for inflammation – acute injuries or pain.  Heat is for achy, stiff muscles with no signs of inflammation.

Of course if you are ever unsure of which modality to use please consult your Dr or feel free to reach out to me directly with any questions.