Interesting to see your comment about stripping wet clothes as I always thought the same and was suprised to read this on the Blizzard site:

"RAF Mountain Rescue’s New CASWRAP System

The RAF Mountain Rescue Service (MRS) has developed a new system to treat and prevent hypothermia while evacuating casualties. Called CASWRAP, it is now being used by all personnel in the UK. Instead of stripping wet clothes from casualties, teams are now trained to wrap them immediately in a Blizzard Survival Bag or Blanket.

More Insulation
They cover this with a conventional sleeping bag for more insulation, then add a second Blizzard Survival Bag or Blanket as an outer layer. When a conventional bag is added as an intermediate layer, even casualties who are soaked warm up rapidly and are fully protected from wind and rain."

Although I suspect is may be more to do with the lack of a controlled enviroment on a mountainside with potentially serious windchill as they also have this on another page, so it seems opinions vary:

"US Army medics are now trained to wrap casualties in Blizzard Survival Blankets as their first response to preventing hypothermia in trauma cases - even in hot weather.

Tens of thousands of Blizzard Survival Blankets are being incorporated in a new Hypothermia Prevention and Management Kit™ (HPMK NSN# 6515-01-532-8056), developed by US military medical equipment specialists North American Rescue Products (www.narescue.com). The HPMK further enhances the Blizzard Survival Blanket's effectiveness with the addition of a self-heating pad and a thermal skull cap.

The Blizzard Survival Blanket is recommended as the first choice for keeping casualties warm by the 2007 Prehospital Trauma Life Support Military Version Sixth Edition (PHTLS Military Version 6E), produced by the globally respected National Association of Emergency Medical Technicians (NAEMT).

PHTLS says medics' initial response to trauma cases should be: “After any immediate life-threatening issues are addressed, wet clothes should be replaced with dry clothes, if possible, and the casualty should be wrapped in a Blizzard Survival Blanket.”

Hypothermia in trauma cases occurs regardless of ambient temperature, PHTLS says, and prevention is far easier than correcting it: so stopping heat loss should begin as soon as possible after wounding.

The guide places the Blizzard Survival Blanket first in a ‘hierarchical equipment list for prevention and treatment of hypothermia'."