We converted our patio (south side of the house) into a sun room some times back. The door to it can be locked from the inside and a key would be necessary to open it. There are no light switches in there.
Not having good luck converting "toy" cuffs into real ones (see earlier posts), I got some "love" cuffs from a small shop in a mall. These came fur lined and I thought of taking it off (when off it's a furry cylinder a little over 7" long), but it helps minimize handcuff rings which can be seen on your wrists. I also have a "Lock'r", a device designed to hold money or a room key after being looped around pool side furniture while swimming. I put a house key in there and looped it around something large and then messed up the preset code to lock it. When I went out there around 4:40am or so handcuffed and closed the door I would be locked out of the house away from the handcuff keys or anything that could be used to pick the lock until near sunrise and I could see to enter the code and unlock it.
The backyard is quite private and I went outside a few times. Doing this several times in several days (probably last chance for quite a while) I saw the moon shift to the east from the day before last quarter (put an eerie light on the back yard) to several days after and saw a bright "star" nearly overhead (turned out to be Jupiter). About ten minutes before sunrise I could make out the number 1 on the Lock'r and figure out how many times I had to move each dial from there.
Today I tried cuffing my hands in front. Didn't do anything for me, I was just sleepy and uncomfortable.
The cuffs I bought were what I was used to in the the keyhole point to the wrist and there is a stop switch ("double lock" on real cuffs). I was surprised there was a safely release lever coming out the side. Since I had the tools and practice I could get the releases off in a few minutes, but if that might present a problem to you, check other cuffs before you leave the store.
Also have practiced freezing a house key, padlock key, and loop of twist ties in a plastic glass and hanging it in the sun room in the afternoon while I wait for it to melt, but I'll save that for another post.