Lydia (Australia) on 06/10/2020:

Therefore, I do believe that saunas and hot baths as well as vigorous exercise (as much as can be safely tolerated), are likely to be very helpful to maintaining and improving one's hearing (as well as eyesight!). Also, it pays to be aware that some prescription medications can have ototoxic effects--as in, they can damage the hearing. In my experience, doctors won't typically warn you because this side effect is considered "rare" (or more likely, hard to definitively link to medication). So the internet is your friend, and just generally, it's best to avoid prescription medications whenever possible, since most of them are prescription-only because they have the potential to cause nasty side effects.

It's not comforting that a serious side effect is rare if you happen to be the one who experiences it.