Thing is, I am not a climber either, but the principle holds.

I can take people snowshoeing in the daylight and it will be a consistent 25F and they will still wear jeans, despite my repeated reminders not to, stomping in deep powder, and suffer miserably with frozen pants and cold legs the entire time while chewing ice out of their bite valves.

I have been stuck in driving snow at 3,000 feet elevation, and stuck in below 25F during the day in July. A cotton blend shirt I reviewed got wet and took a full day in the sun to dry on the back of a pack.

SAR teams call cotton "death cloth" for a reason - the majority of hypothermia cases happen in 40-50F temps in summer, when getting wet and having a little wind chill adds to the problem and people imagine they won't have any troubles because it's "summer."