By Jaden Gillette, PT, DPT

Ice and heat are treatments commonly used to promote healing and reduce pain for orthopedic injuries that have different physiological effects. Ice is a vasoconstrictor, narrowing nearby blood vessels resulting in a temporary decrease in blood flow. Heat is a vasodilator, expanding nearby blood vessels and promoting blood flow to superficial tissues. Both are effective analgesics that help reduce pain.

Effects on inflammation.

Applying heat to the injury site is not advised for the first 72 hours, as it increases blood flow which can lead to swelling. Ice is a bit more controversial. According to the National Institutes of Health (NIH), while ice can decrease movement of fluid from our capillaries to nearby tissues, which may prevent future swelling, it does not reduce swelling that has already occurred at the injury site. Reducing swelling levels can be achieved with medication, compression, or elevation of the body part.

How do I decide which to use, and for how long?

Because of heat’s therapeutic ability to reduce joint stiffness and increase tissue extensibility, it can be used prior to exercise to prepare nearby muscles for increased movement. Ice is typically the best tool following an injury. According to NIH, ice is most effective at reducing secondary tissue damage immediately within hours of when the injury occurred (acute phase). However, its effects are greatly reduced beyond the first 24 hours. You may have heard the old adage to use ice for 20 minutes on and 20 minutes off. Since there is no proven research regarding this recommendation, it is unlikely to provide significant benefit beyond this initial application. Also, several hours of use per day can greatly decrease your overall movement and physical activity levels, which have a much greater influence on tissue healing and recovery.

What role does all this play in the healing process?

NIH notes that the effects of these modalities on the healing process are not as significant as we once thought, as neither ice nor heat have significant ability to speed up tissue healing or improve clinical outcomes, but they can relieve pain.

Here’s what to know:

  • Ice and heat are cheap, simple, and safe pain relievers (analgesics)
  • Ice may assist with minimizing secondary tissue damage if used promptly (within hours) after injury; however, mixed results are noted regarding effectiveness
  • You should apply these modalities for 10 to 20 minutes at a time
  • Neither ice nor heat significantly impacts the healing process or recovery time

Jaden Gillette PT, DPT is a Doctor of Physical Therapy at Excelsior Orthopaedics. For more information on rehab and recovery, visit https://www.excelsiorortho.com, or call 716-250-9999.