Strange Red Rash All Over Face And Body

Hi everyone my little 8 month old son has a rash all over his body and face. On Sunday he started out with fevers and lasted until Tuesday. His fevers got so bad that on Monday they were as high as 103. I took him to the hospital he texted negative to everything including COVID. They just said to keep giving him Tylenol and Motrin. Now that his fevers are gone he this rash has appeared. Does anybody know what this rash is? I am taking him to the doctors but I’m hoping anyone has seen this before?