Might be not so bad for now to stay in until the coat grows a bit. It's summer after all and sometimes they can get really Sun burnt when shaved. Happened to our goddess once and it's not something you want your cat to experience. I mean, it doesn't necessarily mean that'll happen but since the kitty doesn't want to go out... Might as well stay in the shade. After the sunburn the goddess slept a lot, had hot skin and she was cold, not to the touch (she was hot to the touch) as if she was running a fever.
" How we behave toward cats here below determines our status in heaven."
- Robert A. Heinlein