You’re mentioning coming from cold to warm and humidity … my glasses fog up when I come in the house during some of our extreme cold (Nebraska). Are there any precautions I should take this winter?
The conditions I mentioned are different than yours – I’m going from 70 to 90 degree weather outside to 50 degrees and dry inside.
Most aids seem to rated “IP67” which means they’re protected down to at least 15 cm (call it six inches) under water. That doesn’t mean it’s good for them, just that they’re supposed to withstand that.
The consensus is keep them dry and putting them in a dryer made for hearing aids is a very good idea. It could make them last longer.
One thing my audiologist told me: don’t put the batteries in the dryer. They’ll fail.
The bigger threat is probably getting some fine dust carried into the microphone(s) by water.
I know very little about cold weather, but if you need something to keep your ears warm, your aids probably aren’t exposed like your glasses.