WOW, how warm does a F 250 6.7 block heater get?

Mine sits a lot so it is not plugged in normally. But if I will need it or will exercise it I plug it in the night before and use a heavy duty timer set to come on 3 hours before I need it. Starts just fine even in -0 weather, like it has been this week here. That doesn't hurt the electric bill compared to when I just left it plugged in all the time.