Being cold is usually unpleasant, but when it comes to diving, being cold can be dangerous, too. When you become chilled underwater, you lose functionality, strength, and the ability to concentrate on anything other than your own discomfort. In extreme cases, being cold can lead to hypothermia, which is a harmful drop in body temperature to below 95 Fahrenheit (35 C). It can lead to impaired judgment, uncontrollable shivering and, in extreme cases, unconsciousness and death. In addition, loss of body heat is associated with an increased risk of decompression sickness, because when you’re cold, your body constricts its blood vessels in an attempt to conserve heat. In a diving scenario, this means blood off-gasses nitrogen slower than your dive computer or RDP anticipates.