There are rigid, semi-rigid and flexible whole hand, multi-finger and single-finger options -- the easiest way to see them is to Google. I would not use those containing metal on the sides long-term because of the risk of pressure injury.
In the short term, if multiple fingers are affected, you could try the carpal tunnel gloves often available in larger drug stores. You can also make your own using scrap foam from something else, with paper or foam tape. And as others have said, heat, massage, ROM exercises all help.
Best,
Laurie