When you fly over FL350 you are at less than -30 C in the south or in the north. Weather dont make pilots, training makes good pilots, canadians are good pilots, not because of weather, because of training standards. Doing a Cat III landing in heathrow is not one of god misteries, just press the right botton and the aircraft will do it for you, even an ape can do it. Emirates do it all the time and they dont crash because a hot weather pilot or cold weather pilot operates the plane.