Maintaining health is of primary importance to the survivor. Do not take any unnecessary risks which could lead to injury. Aim at a varied and balanced diet and make sure that you get adequate rest.
In the initial stages of a survival situation, none of these may be possible, but once you have a camp established, food sources and water found, a disciplined approach will enable you to conserve energy and resources. Away from people, you are not exposed to contagious infections, unless you brought them with you.
Although some diseases are insect or waterborne, sensible precautions – especially boiling water and properly cooking food – will protect you from many infections.
Extreme climatic conditions bring their own dangers and an awareness of symptoms will help you treat yourself and others. Inexperience or ill-luck may lead to injury no matter how careful you are, and an understanding or practical first aid – improvising where medical equipment is not available – is a basic survival skill.
In accident situations such improvisation may be the first key to survival for those involved, when rapid action is essential. Any expedition should have at least one person with suitable specialized medical knowledge – but EVERYONE should know how to deal with basic injuries, disorders and diseases.