All right so on my left upper arm and left leg I have these little bumps that are soooooooooooooooooooooooooo itchy during the night. They are really red when you scratch them and gets worse when you try to scratch them. And that part where the bumps are located at are hotter than other places of my body. You can kind of see them on my arms in a close distanace. I thnk its my sheets so I did an experiment. One leg wasn't covered by sheets and the other one was and holy crp the one covered was like infested by the bumps. I washed the sheets but still little bumps come up.

It would be difficult to diagnose over the internet.

I would contact your doctor and schedule an appointment.
Or speak to your parents about the bumps.

It could just be a form of dry skin just put lotsof moisturiser on and seeif that helps :) Xx