I've had my 13 Pro for about a week now. I have background refresh turned off for everything. I have noticed it gets pretty warm at times while doing activities that keep the refresh rate maxed out consistently - at least that's the correlation I'm deducing. It's not bad, but definitely warm. It also doesn't always happen. Example - this morning I was navigating through various articles after a search in the Google app, so lots of reading, scrolling, etc. It got pretty warm in about 15 minutes of doing that. But other times, with similar activity, it's fine. ?♂️