Ice should be applied to an acute injury for 10 minutes at a time. Any longer than this could result in tissue damage to the skin by frostbite or lack of blood flow.
Greater than 20 minutes of icing can cause reactive vasodilation, or widening, of the vessels as the body tries to make sure the tissues get the blood supply they need. Studies have also shown 30 to 40 minutes in between icing sessions are needed to counter this reaction.
Never treat with ice for more than 30 minutes, and remove the pack immediately if the injury appears bright pink or red. Don’t use ice packs on the left shoulder if you have a heart condition, and don’t use ice packs around the front or side of the neck.
“It’s perfectly fine to ice if you want, but realize it’s delaying healing,” Gabe Mirkin said, “[ Icing ] is not going to change anything in the long term.” Instead of icing to reduce inflammation, athletes might be better off letting it run its course.
Icing an injury typically takes place immediately after the injury occurs. Using a cold compress or ice pack on a strained muscle can decrease inflammation and numb pain in the area. Icing is effective at reducing pain and swelling because the cold constricts blood vessels and decreases circulation to the area.
Severe burns shouldn’t be treated with ice or ice water because this can further damage the tissue. The best thing to do is cover the burn with a clean towel or sheet and head to the emergency room as quickly as possible for medical evaluation.
Should You Ice a Bruise? Absolutely. An ice pack, bag of ice, or anything frozen placed on an injury when it occurs helps reduce the amount of blood that leaks from the blood vessels into the surrounding tissues.
The problem with using ice as a vasoconstrictor is that, while it limits blood supply and therefore reduces swelling, it also limits arrival of immune cells and thus interferes with core parts of healing.
As a general rule of thumb, use ice for acute injuries or pain, along with inflammation and swelling. Use heat for muscle pain or stiffness.
On the day you get a bruise, apply an ice pack to reduce swelling as well as constrict broken blood vessels. Those vessels then may leak less blood. Avoid heat. In the first two or three days after bruising yourself, a very hot bath or shower could cause more bleeding and swelling.
Injured ligaments heal faster when treated in a way to promote good blood flow. This includes short-term use of icing, heat, proper movement, increased hydration, and several sports medicine technologies like NormaTec Recovery and the Graston technique.
Ice is effective for reducing pain, but it doesn’t speed up the healing process or reduce inflammation. If you want a quick, medicine-free painkiller, feel free to use ice.
Dr. Mirkin has also conceded that ice also delays recovery. The resulting vasoconstriction from cooling, not only reduces tissue oxygenation with necrosis if extreme, but inhibits the inflammatory response needed to initiate healing.
By increasing the temperature and improving circulation, heat can relax injured muscles, heal damaged tissues and improve flexibility. Not only can heat calm pain flare-ups, but it is an excellent way to soothe muscle tension, stiffness and even chronic back pain.