I was out last night in 2 jumpers and a coat with a beanie. (and intermittent use of the hair dryer that is allegedly to get rid of dew on the seconday but also good at warming hands
)
I deceided enought was enough at 2300 with ice on the scopes cover. It was -1 at the time. We had a very hard frost this am. Our birdbath was frozen solid. Brrrrrrrrr