I feel the same as Art, a guard is a trait of a fighting type and or military knife. A guard is not a necessity on an outdoor/bushcraft/survival knife.
You can buy all tha Ka-Bars, AF Survival knives and Gerbers you can haul in the motorhome, as long as you're happy. In many regards a guard or no guard is a matter of personal choice and opinion. Try using the knife for some of the potential camp/survival/bushcraft tasks and see what you prefer.
A good mixed choice is the Grohmann #3 Boat Knife, it has no guard but due to the design the user is fairly well protected so a guard is not needed. You can still do the fine work because it is easy to handle.
As for Hypothermia, unless you get submerged in cold water suddenly, you should be able to avoid hypothermia by proper use of clothing and shelter systems. Don't leave home without the proper gear.