Heat rash?

Does this look like a heat rash? We took my daughter out to a festival today. Outside for about 2 ish hours in the 80 degree weather. She was in her carseat/stroller for the majority of the time. I was nursing her and noticed this rash on her back....weve been home for a couple hours and it's still there.

I'm worried that it's a reaction to something... we started her on green beans a day ago and switched brand of diapers. I googled (I know stupid lol) rashes and it kinda looks like a heat rash but I'm unsure.