Try a light cover or a thin sleeping bag. To be honest, I don’t like to sleep without cover either ! I need the feel/weight of a cover to sleep (even though the weather is hot).

Are you still using a sheet? If not, try that.

Maybe he likes the “fluffy” feel of the blanket. If the baby blanket mentioned above isn’t suitable, and isn’t settling with an ordinary sheet, perhaps try a flannelette sheet or part of one . Another thing you could try is to get a length of winter cotton fabric and hem the ends. If you don’t sew at all, maybe somebody can hem it on a sewing machine for you as you have to prevent the material from fraying.

Try covering him with something lighter, a sheet or bunny rug maybe? Just so there’s something covering him but not too much to make him hot

yeah try a sleeping bag swaddle so he will be warm and somewhat still feel free.

Try using a light summer wrap to drape over him, still has that feeling of being coved while sleeping but won\’t make him super hot at the same time