It's because the Arctic environment. We would often say that we train for winter warfare.
I served for a few years in Valcartier. We used to go out in the back forty, and it would be -40. Now -40 in Valcartier and -40 in the Arctic are not the same things. Until you go to the Arctic, you don't realize that survival brings on a whole new consideration. And you need to get soldiers up there to be able to work in that environment, to be able to move, to adapt, to understand the things they need to do and not do. Working too hard and working up a sweat can threaten your life in the north. So there are things, depending on the environment, that we want to be able to expose our soldiers to and test our equipment in, so that we're able to do that. You can't replicate that down east.
I once saw the tongue from a forklift snap in -40 degree weather, and I thought that was instructive.