M18 What is this rash? (info below)

https://imgur.com/a/Rpdg5su (Taken just now)

M18, got this ‘rash’ a day ago. Its contained to my upper body (Upper back, shoulders, chest, neck)

Been having issues with the heat recently, i get very itchy all over my body when I get too hot and it stays until im able to cool down. However i feel that all over my body (not only my upper body) and it doesnt feel any worse or different where I have the rash. Additionally, I’ve been feeling this itchiness for weeks prior to any physical markings.

The bumps don’t hurt nor itch unless they’re aggravated.

Additional Info: No allergies, no change in habits besides using a new cleaner blanket that Ive never had issues with in the past. Been showering regularly. Have not taken anything for it. Has gotten worse since they first appeared yesterday.

Hoping for some information, im in the exam week of my semester so I dont have so much time to go to the doctors :/ Thanks!