Proper use of therapeutic ice and heat can be confusing. While it is not a black and white issue, there are some general guidelines to follow for best results.
WHEN TO USE ICE:
When you first injure yourself or have a flare up of an injury, it is most prudent to use ice/cold to reduce pain caused by inflammatory products. Ice packs kept in the freezer work well for large areas such as back, hips, and neck. Make sure to put a towel between the ice pack and your skin to avoid ice burns. For smaller regions such as hands, feet, or ankles, filling a bucket with ice water and submerging is your best bet. If the area is focused, such as one side of your knee or elbow, holding an ice cube in your hand with a towel and moving back and forth over the area works best.
Another scenario when cold is effective, is after a long distance run, bike ride, or other cardio activity. Filling a bathtub with very cold water from the waist down and sitting for as long as you can stand it can reduce the effects of DOMS (Delayed Onset Muscle Soreness). For this, I recommend wearing a sweatshirt and drinking hot tea to take the edge off.
When treating with ice, your sensations move through a few phases: Cold, Burning, Aching, and finally, Numbness. During the first 3 phases you may feel the urge to quit. Hang in there!
WHEN TO USE HEAT:
Heat works best for chronic tension and relaxation by increasing blood flow. As with ice, hot packs work great for large areas making sure you have a towel between the pack and your skin to avoid burns. Hot water buckets for hands and feet/ankles. Hot baths for overall body relaxation. Adding Epsom Salt (found at any grocery store or pharmacy) to a hot bucket or bath boosts the relaxing effects.
Warning: Using a hot pack after you first injure yourself can increase pain and can make an injury take longer to heal. Ice is your best bet for this phase.
WHEN TO ALTERNATE BETWEEN ICE AND HEAT:
Alternating between ice and heat is best for circulating blood through an area. At least 72 hours after an initial injury, you can begin to alternate. Heat increases blood flow by dilating the blood vessels. Ice flushes the blood away by constricting blood vessels. For this reason, it is best to end on the ice phase to pump the blood.
HOW LONG TO APPLY:
Always use the “20/60 Rule”. This means 20 minutes of ice/heat and then 60 minutes off. You can repeat this as many times as you want as long as you are taking the entire 60 minutes off after you finish your treatment. If you are alternating between the two, 5 minutes of each up to 20 minutes total (heat, ice, heat, ice). NEVER SLEEP WITH A HOT PACK IN YOUR BED THROUGH THE NIGHT!
***The reason that initially stated that this is not a black and white issue is that these treatments are subjective, and it is not always clear what phase of healing your body is in. Use these as general guidelines, but do what feels best and yields the most effective results.