A well-stocked first-aid kit can help you respond effectively to common injuries and emergencies. Keep at least one first-aid kit in your home and one in your car. Store your kits in easy-to-retrieve locations, out of reach of young children. Make sure children old enough to understand the purpose of the kits know where they're stored. You can buy first-aid kits at many drugstores or assemble your own. Check your first-aid kits at least every three months to be sure the flashlight batteries work and to replace supplies that have expired.