I'll have to dig and find out who built this. Beautiful, isn't it? How fun to snuggle up in front of the window with a battery operated heater of some kind nearby (is there such a thing that wouldn't spark flames?), popcorn, thermal underwear, those sub-zero sleeping bags, hot chocolate.... I bet the view is amazing. Oh, and those socks and gloves that heat up would be good, too. FYI, the opening is a window so you would not be totally exposed to the elements.
My apologies to those wonderful people who built this. I'm going to go in search of your identities right now.