60yrs. old, I make sure that I don't eat too much before tours, it actually makes my energy level seem to go up with less food.
I wash my hands often and gargle when I can since in October some customers will cough right in your face! (I don't cough in their face.)
I go outdoors and back to the warmer inside confines then to a 52 degree wine cellar, up to a hot attic cupola.. but then years ago working in a food store going from the walk-in freezer and then carrying grocerys out into a 90 degree parking lot was no piece of cake either!
If you have enough food-energy in you the cold doesn't seem to bother nearly as much.
Last night after the last customers were gone it still took me 45 minutes of walking, carrying, just plain old "Work" to shut down, lock up, inspect, reset the place, once I was done I just lay down, close my eyes and then it's morning, the buzzards circling my still body must make them do that Alarm clock thing.
Think I'm their meat/breakfast.