Beast of Burden
I've had this too. A few years ago, my aunt fell badly and cracked her skull open during a family holiday in Montenegro. I was the first one to get to the hospital, which was tiny and poor, and I had to help the nurses get her onto an operating table, undress her, turn her over, etc, whilst they did all the initial. Everybody else had basically gone to pieces, but I managed to switch out of the situation and step in. For that moment, switching off the emotion was very useful.