I would say give him space.

I have gone through multiple periods of dealing with psychosis/paranoia, and mine also tends to get worse at night when it's happening.

This can spike anxiety and agitation very badly, and one thing that many of us afflicted worry about is accidentally harming (verbally or physically) our loved ones in the midst of freaking the hell out. Sometimes this concern is only deep down and subconscious, and on the surface, we simply just don't want to lose control.

So getting away and getting some space can be very important. It gives us time and space to cool off, talk to ourselves and do other self-soothing skills without anyone around to judge us or be weirded-out by it. Things like walking/pacing, exposure to cold, smoking, etc are common ways we might "bring ourselves back down" and clear our minds.

If an adult with these struggles needs space, it is important to let them have that space. If it is cold outside and they have been gone for more than an hour, it is not unreasonable to call and expect a quick "I'm okay" from them, as a deal of sorts so that space can be given and loved ones don't have to worry.