Today’s Topic: Hypothermia. Hypothermia means low body temperature, clinically defined as a core temperature below 95F (35C). Symptoms include: Loss of dexterity and motor control, mental confusion, then unconsciousness. It takes as little as 30 minutes for an adult of average size to lose dexterity in waters of 60-70 degrees, and as little as 2 hours to become unconscious. Without a PFD, this will likely result in drowning.