Mt Rainier makes it's own weather. It can be sunny at the base
and a blizzard part way up. Like Mt Hood, it is a serious
mountain. No Heet Sheet is going to hold up to the winds or keep
out a blizzard. Sometimes 4 season tents don't survive.

Climbing to camp Muir is
not glaciated and when the sun is out the trip seems a nice long hike as there are no ropes etc. involved.