One of the questions we got the other day is how to properly wear a balaclava. We were asked if you should tuck it in or not tuck it in. Actually, either way is acceptable. There's no mention of this in the NFPA 70E standard. Firefighters often tuck it in because they're wearing a turnout gear that they put over top. The balaclava goes over top of the shirt and then they put the coat over top and close up the coat, which means that the balaclava is tucked in. That means that flash fire can't get up underneath it. In an arc flash, this is not very common and I know of no accidents where somebody had energy that came up underneath their balaclava and burned them.
So wear your balaclava. It's primarily to protect the side of the face, the back of the neck, and the front of the neck, and it's really protective when you wear it in arc flash.