Why are mittens still made? Are there advantages over gloves?

Stupid memory of a drill sarg giving me shit because, when we were doing something out in the cold, I had the temerity to curl my fingers up in my gloves rather than sticking them down the finger holes. That, and unbuttoned buttons are why me and the army were a bad fit.

« He got frostbite and may lose a fingertip or two, but man, he looked sharp! »