context: When your joints are painful or your muscles ache, topical pain killers -- those you apply to your skin -- may offer relief. You'll find many products for topical pain relief at your local drugstore. Here are some popular options and what you need to know if you'd like to give them a try. Topical pain killers, or analgesics, are sprayed on or rubbed into the skin over painful muscles or joints. Although are all designed to relieve pain, different products use different ingredients. Here are the most common ingredients found in products available without a prescription. Counterirritants. Ingredients such as menthol, methylsalicylate (oil of evergreen), and camphor are called counterirritants because they create a burning or cooling sensation that distracts your mind from the pain. Salicylates. These same ingredients that give aspirin its pain-relieving quality are found in some creams. When absorbed into the skin, they may help with pain, particularly in joints close to the skin, such as the fingers, knees, and elbows. Capsaicin. The main ingredient of hot chili peppers, capsaicin is also one of the most effective ingredients for topical pain relief. It can be helpful for joint pain and for diabetic nerve pain. When first applied, capsaicin creams cause a warm tingling or burning sensation. This gets better over time. You may need to apply these creams for a few days up to a couple of weeks before you notice relief from pain. Here's what you need to know to get the greatest effects and minimize the risks of these products: Read the package insert and follow directions carefully. If there is an insert, save it to refer to later. Never apply them to wounds or damaged skin. Do not use them along with a heating pad, because it could cause burns. Do not use under a tight bandage. Wash your hands well after using them or wear gloves. Avoid touching your eyes and genitals with the product on your hands. If you are allergic to aspirin or are taking blood thinners, check with your doctor before using topical medications that contain salicylates. Hot or cold packs -- or sometimes a combination of the two -- can provide relief for sore muscles and joints. Cold numbs sore areas. It is especially helpful for the pain and swelling of an arthritis flare or joint injury, such as a sprained ankle. Cold may reduce inflammation by constricting blood flow to the injured area. You can apply cold using a commercial cold pack or with a water bottle filled with ice and cold water. You can also use items already in your home such as: Zippable plastic freezer or storage bags filled with ice and water A wash cloth or hand towel dipped into cold water and ice A bag of frozen vegetables, such as peas or corn Heat packs relax your muscles. Heat dilates blood vessels, sending more oxygen and blood to the area. Heat also decreases the sensation of pain. You can apply heat with commercial heat packs, heating pads, or hot water bottles. Other ways to use heat include: Soaking in a hot bathtub Standing under a hot shower Soaking a washcloth or hand towel in warm water then applying to painful joints or muscles To get the most relief from hot or cold without damaging your skin, try these tips: Use either heat or cold for only 15-20 minutes at a time. Place a towel between your skin and the cold or heat source. Don't use heat or cold on skin with open cuts or sores. Don't use cold packs if you have vasculitis or poor circulation. Test the temperature before using heat or cold. Do not use creams, heat rubs, or lotions on your skin while using a hot or cold treatment. Be especially careful with heating pads, which can cause severe burns if too hot or if left on for too long. Do not make your bath or shower water too hot. This may cause dizziness or fatigue.