Ftm, my baby’s rash is spreading any tips to help?

My baby was born with small amounts of rash on his back and face and the doctor said it was normal. However after his 6 day visit I notice they were getting more. I researched it and it is called milia but yet I’m also being told that it is mixed with heat rash (it’s hot where we live). Any mamas out there can help me get rid of his rash? I already took him to the doc and they say it’ll go away a few weeks but if there are ways to get rid of it faster without hurting him I am all ears