Icing and heating can bring essential relief to common problems musicians have. If you're encountering severe or chronic pain, the BEST thing you can do is to immediately seek out a physician. Head to an osteopath, a physical therapist, a sports certified massage therapist, whoever can give you a trusted opinion and reference this for what it is, a rough guide to a personal problem.
When to Ice
Ice is for bringing down swelling and slowing down circulation to tissues that are inflamed. It's best used for dull aches over taking a painkiller. If you have a new pain that has recently developed and isn't recurring, it's likely time to ice. I try to follow my running/hiking and general CPR training advice which is represented with the acronym RICE.
For example, if I have a new cramp in my thumb from a really long day, or a little soreness in my left forearm from a gig with particularly heavy finger movement or fast sections, at the end of rehearsal it is time for rest (not more practicing!) I'll head home in the evening and add an ice pack, 20 minutes on 20 minutes off. Before bed I'll wrap up my arm or add a compression sleeve I have from running and while I settle down to watch a show on Netflix, I'll prop my arm up, above heart level, on the back of the sofa or a pile of pillows.
When to Apply Heat
Heat is for chronic pain, muscles that ache repeatedly, and stiffness. This is because a lot of our chronic join pain is stemming from muscle tightness. The best thing to do is to improve circulation to these stressed muscles and allow them to relax. Not only can blood flow help relieve muscle tension, it can help relax the nervous system which also leads to muscular tension.
I often heat a sock filled with rice before bed and place it at the back base of my neck or under my lower back to get the blood flow circulating to these consistently tight areas. Heat should never be used for new injuries; it will make them worse!
Here's a handy guide to a few common musician problems:
If your soreness is from a one-time long day or a particularly tough session, add an ice pack.
If your soreness is a repeating problem brought about from overuse and strain, add a heat pack.
If you are in extreme pain, can't identify the difference or find the suggest treatment aggravating, REST and seek out a medical professional.
Remember, our bodies should never limit our art so learn how to train like an athlete to play like a musician.
Less pain and more joy!