The Association of Chartered Physiotherapists in Sports Medicine recommends only using ice packs for a maximum of 10 minutes at a time on areas where the skin is close to the bone, and up to 30 minutes on areas with more fat or muscle. ALWAYS cover the ice pack or the affected area with a cloth, towel, or elastic bandage.
The video below shows a second degree burn and frostbite due to leaving a gel ice pack on an injured area for about 45 minutes along with no barrier between skin and gel ice pack. The video shows the sequence of what occurs in a 10 hour span. Viewer discretion is advised.
**UPDATE** AFTER DOCTOR VISIT. VIEWER DISCRETION ADVISED.