Using heat or cold therapy to address pain can be extremely effective for many different conditions and injuries. The difficult part is knowing what situations call for hot, and what call for cold.
Heat therapy
Think: heating pads, saunas, steamed towels and hot baths.
Heat therapy improves circulation and blood flow to the concentrated area (where you’re applying increased temperature). This helps soothe pain, heal damaged tissue and increase muscle flexibility.
When applying heat, you can choose to do so locally, regionally or across the whole body. Local treatment is best for small areas of discomfort, like one stiff muscle. Heated gel packs work perfectly for this. Regional therapy is better for widespread stiffness and can be done with a steamed towel or a large heating pad. When the whole self is in pain, full body treatment includes options like saunas or hot baths.
Heat is most effective when applied for a long time. Minor stiffness is usually relieved with only 15 to 20 minutes of heat, but moderate to severe pain needs between 30 minutes and two hours to alleviate symptoms.
Cold therapy
Think: ice packs or frozen gel packs, coolant sprays, ice massages, and ice baths.
Cold therapy, also known as cryotherapy, works by reducing blood flow to a particular area. This reduces inflammation, swelling and nerve activity that causes pain—especially when experienced around a joint or a tendon.
Only use cold therapy for short periods of time (10 to 15 minutes). Experts are adamant about no more than 20 minutes of cold therapy per session, which can cause nerve, tissue and skin damage.
For worse pain, it’s best to apply the cold compress several times a day. You can elevate the damaged area at the same time for greater relief.
Knowing when to use heat or cold treatment will help to alleviate discomfort. In summary, as a general rule of thumb: Use heat for muscle pain or stiffness, and use ice for inflammation, swelling and sharp pain.
Sources:
https://www.healthline.com/health/chronic-pain/treating-pain-with-heat-and-cold
https://health.clevelandclinic.org/should-you-use-ice-or-heat-for-pain-infographic/