Without treatment, this slide leads to stupor, collapse, and death. When clothes get wet, they lose about ninety percent of their insulating value. Wool loses less as does many of the new synthetics. Cotton and wet down are worthless. A slight breeze carries heat away from bare skin much faster than still air.
Wind drives cold air under and through clothing.
Wind refrigerates wet clothes by evaporating moisture from the surface. Direct sunlight on the skin helps in the warming process. Most hypothermia cases develop in air temperatures between 30 and 50 degrees. Most outdoor enthusiast simply can't believe such temperatures can be dangerous. They fatally underestimate the danger of being wet at such temperatures.