Immobile, fumbling hands. Persistent or violent shivering is a clear warning that you are on the verge of hypothermia. The body is trying to create heat by stressing the muscles. This drains your energy reserves and if continued, will produce fatigue. Tired victims with low energy levels can quickly become hypothermic without their knowing.
Person curls up into a fetal position to conserve heat.
Try to open their arm up from the fetal position, if it curls back up, the person is alive. Dead muscles won't contract only live muscles. Skin is pale, pupils dilate, pulse rate decreases, the person looks dead but is still alive. At 90 degrees core temperature, the body tries to move into hibernation, shutting down all peripheral blood flow and reducing breathing rate and heart rate. The purpose of the following is only to familiarize the layman with a basic understanding of treatments and is not intended to be an authorative reference source.