If conditions get really bad be smart enough to give up reaching your destination or whatever you had in mind. Get out of the wind and rain. Build a fire and concentrate on making your camp as secure and comfortable as possible.
Make camp while you still have an energy reserve. Allow for the fact that exposure greatly reduces your normal endurance. You may think you are doing fine when in fact the only thing preventing you from going into hypothermia is the fact that you are exercising. If exhaustion forces you to stop, however brief, your rate of body heat production instantly drops by fifty percent or more. Violent, incapacitating shivering may begin immediately. You may slip into hypothermia in a matter of minutes. Hypothermia is caused by both the cold and exhaustion.
If you or your group is exposed to wind, cold, or wet, think hypothermia.
Watch yourself and others for the following symptoms:
Uncontrollable fits of shivering.
Vague, slow, slurred speech.
Memory lapses or incoherence.
Immobile, fumbling hands.
Frequent stumbling.
Drowsiness (to sleep is to die).
Apparent exhaustion (inability to get up after a rest).
A person needing treatment for hypothermia may deny they are in trouble. Believe the symptoms, not the person. Even mild symptoms demand immediate treatment.
If the victim is only mildly impaired.
Give them warm drinks and only in small amounts. No alcohol, coffee or tea.
Get them into dry clothes and a warm dry sleeping bag. Well-wrapped warm (not hot) rocks or canteens placed in the crotch and under the arms anywhere the main arteries are close to the surface of the skin, will hasten recovery. Always remember, gentle handling, and don't try to re-warm a patient too fast.
If the patient is semi-conscious or worse.
Try to keep them awake. (Do not give hot liquids by mouth.)
Leave them stripped. Put them in a sleeping bag with another person (also stripped) to transfer heat. If you can put the person between two donors, skin to skin contact is very effective treatment. Always act on the premise that "no one is dead until warm and dead".
Transport the victim as soon as possible to the closest hospital for monitoring. It takes a very long time to warm the inner core and only a rectal hypothermia thermometer is long enough to find out what the inner core temperature really is. Don't delay!
Loss of body heat to water is a major cause of deaths in boating accidents. It should also be noted that alcohol lowers the body temperature about two to three degrees by dilating the blood vessels.
Water Temperature Exhaustion or Unconsciousness Survival
32.5 F Less than 15 minutes 15 to 45 min.
32.5 to 40 F 15 to 30 minutes 30 to 90 min.
40 to 50 F 30 to 60 minutes 1 to 3 hrs.
50 to 60 1 to 2 hours 1 to 6 hrs.
Personal flotation devices, better known as life jackets, can increase survival time because of the insulating value they provide.