There are approximately 640 muscles, 206 bones, 900-plus ligaments, and 4,000-plus tendons in the human body. Even if you lead a sedentary lifestyle, you’re bound to sprain, strain, bump, or bruise some of them from time to time. When you experience pain that’s bothersome but doesn’t quite meet the threshold for making an appointment with your orthopedic doctor, you probably head to your medicine chest and take an aspirin or acetaminophen tablet. If the pain continues you may seek relief from a heating pad or an ice pack. Before you administer hot or cold therapy, make sure you’re using the right one. Otherwise, you could do more harm than good.