It’s a question we frequently get asked by patients – how long should an ice pack be applied for, and how often? Is it 20 minutes on, 20 minutes off? Once every two hours? Can you overdo it?

Ice packs are the most common treatment for acute injuries. We’ve all heard about the R.I.C.E acronym. But surprisingly little research has looked at the ideal protocol.

Current best practice is guided by a mix of clinical research and knowledge of physiology.

How and why

• Each ice pack application should last 10 to 12 minutes
  • This gives enough time for the cold to affect deeper tissues but avoids the body’s protective response to cold, the Hunting reaction. This reaction increase local blood flow after around 15 minutes to re-warm the area, resulting in a reversal of the effect of the ice pack
• There’s no guidance in research studies on the time between applications but about every two hours seems to provide the greatest clinical benefit

Which type of ice application

• Ice packs work well for most injuries, particularly on flat areas such as calf muscle tears and thigh injuries
  • The best ice pack is the good ol’ 1kg pack of frozen peas – enough bulk to stay frozen for an application and perfectly malleable
  • Another great alternative is a Ziplock bag with a handful of ice cubes and some tap water (about 1/3 full). Ice cubes slowly chill the water over 5min, then it stays cold for another 5min. We typically double bag it (Ziplock bag inside another bag) in case of leaks.
• Ice massage (rubbing an ice cube directly on the area) works a treat for superficial injuries, such as Achilles tendinopathy and Plantarfasciitis
  • It’s quicker to apply than ice packs (as the cold doesn’t have to penetrate as far). Usually around 3-5min is all that’s needed
  • Wrap the ice cube in a paper towel so your fingers don’t get cold burns.
• Ice immersion (bucket of water and plenty of ice cubes) works well for complex shapes, such as hand injuries and ankle sprains
  • Use a bucket big enough to fit a foot without having to twist it awkwardly
  • Use tap water and 12-20 ice cubes, placing the foot in from the start (don’t wait for the water to chill)
  • Agitate the water every minute to speed up the chilling effect. This also ensures the ice doesn’t rest against the skin for too long and cause an ice burn
  • This application requires 20min total as it takes around 10min for the water to reach a sufficient temperature to chill the injury