If playing in 5760x1080 as I usually do, grab some screenshots, then make a snap decision whether I think I can win. If not, run like hell. If so, fight.
If playing in 1920x1080, that means i'm probably already recording (Shadowplay doesn't work in Surround mode, it seems, so I play in single monitor when recording). If not, I'd fire up Shadowplay. Hopefully, I'd get some good footage of the ensuing melee while I try to do humanity honor whether I live or die!