Not so great an idea. You might be seeing the northern lights from your bed, but your room will be radiating all its heat out through that big glass roof.
It's the same physical principle behind why your car can have frost on it in the morning even if the air temperature never gets below freezing over night. Your car is radiating heat into everything including and especially the very cold air in the upper atmosphere above it.
DerStickler is exactly right. Heavy cavalry armor was used on horses. That's why the legs were covered in metal, because you didn't run and legs were easy to reach from the ground. Infantry armor is designed differently because many more blows come from above than below and you need to be able to move on foot in it.
No they haven't. They've theorized a possible solution. The other answer, that they haven't known what they've been f***ing talking about for the past 20 years, just isn't as palatable to them or the people who write their checks.
Honestly, that article gives Galen an undeserved bad rap. He didn't invent or popularize the humors theory (that was Hippocrates). He also had a much more thorough knowledge of anatomy than any of his peers because of his work with the legions and gladiators.
It's the same physical principle behind why your car can have frost on it in the morning even if the air temperature never gets below freezing over night. Your car is radiating heat into everything including and especially the very cold air in the upper atmosphere above it.