Is this heat rash?

I'm a first time momma. This didn't happen to her when she was born last summer. However we've been put a lot this summer. Last year we couldn't because of all the smoke from the wildfires.

We won't be going outside in the sun until it clears up. She's just running around in her diaper. It doesn't seem to be bugging her at all.

I literally had no idea what a heat rash even was until recently. If this is what this looks like, great. Any advice would be appreciated.

If it looks like something more serious and you think it warrents an immediate doctor visit, say so please. I'll have to call my husband to come home from work.

It's only on her torso and neck. There's a tiny amount on her face. It's nowhere else though.

I'm pretty sure it's a heat rash from what I've read. I just want to put my mind at ease 😂