iPhone X and 7 get warm

Looking to see if people’s phones match up to what I experience yesterday in a car my iPhone X get pretty through the entire phone when I got out and was able to check the temp with a thermometer the phone was 90 degrees on the back and felt warm against my skin this was just idling in my truck with the ac on. I can easily make both my iPhone X and 7 ramp up over this with just general usage such as browsing the internet or facebook but usually this is under the camera.

Is it normal for a phone to feel warm when idling in my lap while driving with the AC on? The whole phone felt warm at this point. Roughly 80 degrees outside yesterday.

All of this is in Fahrenheit also what temp is your phone f you can check for me. Any thermometer will work.

Thank you so much, also my previous X was replaced I have had this one since Friday, updated to 11.4 Wednesday.