 Fill your refill before it completely runs out. Have a little bit on store. You need to have a way to have clean water. There are several ways you can do that, including boiling and other ways. As far as pure medical supplies, some bandages and just your typical type of stuff like Band-Aids and Betadine, which is an iodine solution. If you're not allergic to iodine, it's a good way to disinfect water. And have a first aid book available everywhere.