By Cameron Hobbs

 (B.App Sc. Exercise & Sport Science; M.Physiotherapy)

‘Should I be grabbing the peas from the freezer or my hot water bottle?’ As a physio, I often get asked this question by my clients. The simple answer is that both are useful treatments! However, the key is to identify the nature of the injury and the timing of application. Below is a simple outline of each modality and when it is most appropriate.


When to chill out?

Ice, or Cryotherapy, is generally used when an injury is less than 24-48 hours old. With any sprain, strain or bruise, tissue damage stimulates our body’s inflammatory process. Despite this process being a necessary one, it is important to minimise the degree of swelling. This will allow us to begin the rehabilitative process quicker and minimise the negative compensatory patterns that can develop post-injury! So as a simple guide, the immediate aim of using ice is to:

  • Reduce bleeding in local tissues/structures
  • Minimise the amount of inflammation
  • Reduce muscle pain and spasm via nerve desensitisation
  • Numb the local soft tissues
  • Minimise the effects of Delayed Onset Muscle Soreness (DOMS) following a heavy workout

Here are also a number of tips to consider when applying ice:

  • Always aim to apply the ice as close to the injury onset as possible (this also includes after a heavy workout)
  • Wrap the ice pack in a moist towel to minimise the risk of ice burn
  • Ice only needs to be applied for 20 minutes to have a physiologically worthwhile effect. However, aim to perform every 1-2 hours during the initial 48 hour window to minimise the inflammatory process and the risk of tissue damage from prolonged cold exposure
  • Gravity can often shift the location of bruising/swelling, so make sure you apply ice to the original injury site!


When to turn up the heat?

Heat, or Thermotherapy, takes centre stage in the rehab process after the first 48 hours. At this stage, the inflammatory process has mostly subsided and healing has begun. The focus now becomes the restoration of range of movement and strength whilst still minimising pain symptoms. This is achieved via the dilation of blood vessels, which in turn reduces muscle spasm. Here are a number of tips to consider when using heat:

  • Heat only needs to be applied for 20 minutes. The heat pack should be wrapped in a towel for insulation against any burns to the skin. Aim to re-apply every 1-2 hours
  • If swelling is still present, continue to use ice until this has subsided
  • Avoid using heat if the injury is an open wound
  • If the injury is a re-occurring muscular spasm, heat can be considered an appropriate first line of management.


So in Summary…

Remember that the stage at which you begin using ice or heat post-injury is the key factor in almost all scenarios! Application should be long enough to create the desired effect of cooling/heating the site, but not so long as to cause tissue damage from over-exposure. And finally, make sure you have your injury reviewed by a physiotherapist so that an appropriate rehab management plan can be devised. Even a simple ankle sprain can pre-dispose you to long term instability when not appropriately rehabilitated. Best of luck with your students!