I was shaving my head with a beard over a year ago before I shipped, then for a while I was shaving head and beard after I joined. When I had a beard everyone said I looked like an MMA fighter. No one seemed any more scared of me than usual, even people who didn't know me, and I'm known to look mad even though I'm usually not. Your head shouldn't be any colder than it is when you clip it, and the first night after you do it the pillow feels amazing against the skin of your head.
If you aren't sure about it, just give it a go. After only a few days your hair will be the same length it is when you clip it, so it's really no big deal.
Now shaving your head AND shaving your beard? Naw, forget that. Makes you look like a serial killer, even if you do happen to be in the military.
Current PRs at 242, raw w/ wraps- 525, 355, 605, 1485
Roboro tui, perimo vester adversarius
(Build yourself, destroy your enemy)