First of all, wherever there is adventure, there is also danger. The most important item that you must take with you is a first aid kit. You don't need to buy a special kit; you could easily make your own. You need to include some painkillers, some cream for insect bites and sting, and gauze and bandages for any injuries. If you don't think you'll be able to buy them on vacation, it's also a good idea to take throat lozenges and pills for an upset stomach. Don't forget to pack the sunscreen, either. The sun doesn't only burn you on lazy beach vacations. You can get sunburned when you're sailing, hiking, or cross-country skiing, too