Unless you have information to confirm, I wouldn't automatically assume there is going to be a problem.
Does he live in a stable/barn, Yes- then he does indoors.
Most of the "problems" horses have are owner/rider problems.
Of coarse there are those horses who don't like indoors. You need to stay calm and reassuring, be very aware of your breathing. If you are truelly scared/nervous don't ride, your horse will be bad. If you need to have him rode, find a catch rider. But if you can contain your nervousness, just ride, the same as any other day any other ride. If you don't create a big deal, there won't be one.