How soon would death occur from /Hypothermia in cold water?

Answer 1

Depending on the water temperature and amount and type of clothing, shock can cause unconsciousness in less than 30 seconds in the majority of individuals exposed to such conditions, which would then of course result in drowning in an additional 20-30 seconds. However, at extremely low temperatures, the body can survive hypoxemia of the brain much better than at normal temperature. There have been resuscitations after several minutes at body temperatures well below those which normally cause death.