What rash could this be?

My son broke out last night in a rash, I washed him off with a cool rag from head to toe, I kept him up for a while making sure it wasn’t affecting his breathing because I’m unsure what it is.

He hasn’t ate or drank anything new, we haven’t used any new detergents, he hasn’t been anywhere. He hasn’t crawled into anything, this was just so weird and random. It’s progressively getting worse. Any ideas?

I don’t have transportation right now to take him to the doctor, his dad is at work (they ride in a van, park cars at random meet up places and go out of county for chicken production work) and my mom is at work, my sister isn’t answering and I feel so stuck. I’m still calling and texting them all trying to get a reply and have yet to get one and it’s been an hour.