Do not embark on such a project if you have some chronic conditions. Start in a good shape. Generally keep a healthy lifestyle: no heavy drinking, no junk food dinners, enough motion, etc. Stay away from high-risk pastimes like snowboarding, motorcycle racing, etc. Wash your hands and do other trivial things to keep infections reasonably away, especially when far from thickets of civilization.
Things like that. Do what you can not to get badly sick or injured, because medical bills can quickly burn through your savings.