On days like today (high of 20°F in New York City), I often wonder how close I am to hypothermia. Wikipedia defines three stages of a cooling body temperature:
- Stage 1 (1-2°C below normal body temperature): light shivering and goosebumps (which are ineffective in humans)
- Stage 2 (2-4°C below normal body temperature): with strong shivering, pale skin and blue extremities
- Stage 3 (8°C below normal body temperature): puffy blue skin, cognitive failures, “terminal burrowing,” “paradoxical undressing,” and eventually death
The verdict: keep your head covered and don’t fall in the water when it’s butt cold outside. If you take off all your clothes and start burrowing, the end is probably near.