A baby with a fever and red spots on the back is likely to have a viral infection causing the fever and rash. First, you need to go to the hospital to check the C-reactive protein and blood count, and also have the doctor look at the rash to rule out measles virus or other types of infections causing the red spots. If a viral infection does occur, it can be treated with antiviral medication. If the temperature of the fever is high, you should also use antipyretic medication, such as ibuprofen suspension or acetaminophen pellets, during the fever, which are more effective in reducing fever. For the phenomenon of red dots, if there is no itching, try not to scratch, if itching occurs, you can use furnace glycerin lotion for local application, the effect of anti-itch is better, to drink more water to promote the discharge of toxins in the body. Secondly, the consumption of water during fever is relatively large, so it is also necessary to drink more water.