Hi Shelly; From the frozen north of Canada I concur that the cold air does quite a number on a radiated throat. There is still such tender thin tissue back there at your husband's stage of recovery, he will have to sip and sip in any situation where the air is dry.
Yes, I agree that air conditioning has the same effect (ouch). I keep the mist machine on at night and keep the house well humidified during the day.
For those who live in winter-lands we have to guard our throats in cold and dry conditions.
Even when visiting folks..I sometimes have to ask for fluids because it doesn't occur to them that because I am not drinking alcohol that I don't need anything to drink.
Like most of us, your hubby probably goes nowhere without a couple of bottles of water. We paddle our own canoe right.
Godspeed you two in your recovery,
Fran