A large, heavy-duty bag can serve to help keep you dry for a short period of time by punching a hole for your head. It also becomes invaluable as an emergency sleeping bag. Also bring some high energy food and plenty of water. Leave your hiking plans with a reliable person and an expected time back. Hazards Hypothermia is an extremely serious condition on the trail.
Early signs are uncontrolled shivering and slurred speach.
A hypothermic person will have impared mental capabilities and may not recognize the seriousness of their situation or take appropriate action. Mild cases should be treated by rewarming in dry clothing, this can be done with the body heat of another person in a sleeping bag. If the person has stopped shivering, the condition is much more serious and immediate medical assistance is necessary to prevent death. Don't drink untreated water. Bring along at least 2 quarts per person per day.