In the last few months I came across Peter Kummerfeldt’s survival web site:

http://www.outdoorsafe.com/index.htm

and I've found his philosophy of pre-planning and simple/small/lightweight but effective equipment that is ALWAYS carried with you to be very sensible.

Anyway, to the point of this thread ... he says "Dress to survive not just to arrive!". I think of that often when heading out on local winter car drives. I tell my kids to think about whether they are dressed warm enough to stand outside for a few hours if we get into an accident.