8 month old has a rash on arms legs and cheeks?

my 8 month old has had this rash on his cheeks arms and legs.
his cheeks are really red and has lots of red bumps on his cheeks and around his mouth.
his arms and legs have small rough bumps around ankles and wrists which are placed pretty closely together as you go up the arms and legs the bumps seem to spread apart and arent so closely placed to each other

it hasnt seemed to spread from any of these areas and nothing i have put on it is seeming to help make it go away…. ive tried calmine lotion diaper rash cream and a prescription cream that the docs gave him nothing is making it go away

i think that it may just be what all babies get. it may be from exposure to the sun too much so try and put sunscreen on him when you go out all the time. even if it isnt hot outside. just cause it is cold doesnt mean that the uv rays that burn arent there

It is only on my arms, on the parts not covered by my tshirt. I’ve had this happen every summer for several years. heat rashyou need to go and see the doctor.