Haha. That implies you could be thawed back to life? :) Which I suppose a rez would technically do!
(Note: You can already die due to freezing in the game, remember that frozen climate they showed in a stream a while back? Without proper acclimation you take damage over time till you die)
Not that I wish to encourage the dreaded 'scope creep' monster, but this might be a fun result from having some amount of cold acclimation, but not enough for a particular situation. Anyone entering with none, you just frost up normally until you're dead. Enough, and you pass thru unscathed. Some amount in between, and you just slooooooow down gradually until you are frozen in place. Able to call for help, but unable to use abilities or retreat. With a suitable timer on the frozen state and if you don't get rescued then ultimately you die.