Blisters are painful and uncomfortable but are common and usually heal within 7-10 days. A good overall rule is to leave the skin intact if possible. If extremely painful, you can gently pop the blister with a sterilized needle, but do not tear it. The extra skin will act as a barrier to keep out bacteria and dirt. Wash the area and cover it with a bandage. Tape over the area to keep it clean and dry. If you're without a bandage, you can create a makeshift one by folding a piece of tape over onto itself. Place the folded section over the blister and secure it.