I have responded in another thread about this same issue. I have model #A2251. The device felt hot to the touch so I purchased a third party app to monitor the temp 'Battery Monitor.' The temp consistently runs between 90 - 100 degrees regardless of what I'm doing. The fan NEVER kicked on. I am not a gamer, or heavy user. The most I ever do is stream on Hulu, Netflix, or Prime. I previously had a 2017 MacBook Air that didn't get this warm, ever.
After several calls to Apple, then having me reset the SMC, run in safe mode, run a diagnostics I made an appointment at my local Apple store. After doing some things to the device they sent it back to Apple. Apple replaced the Logic Board, Touch ID board, and 'clean' installed the latest Mac OS version (side note: it was not the latest version, I had to do an update). I received it yesterday afternoon. Reinstalled my files (files, Outlook, Word, Excel) from TimeMachine and am using normally this morning.
Currently I have open this page (Safari), Chrome, Outlook Mail, Messages, and Battery Monitor and the temp is sitting at 95 degrees. Still no fan has come on. The bottom is extremely hot, the top uncomfortably warm.
Apple did ask me multiple times if I am using the device on a table or desk. I told them that yes, I do that sometimes but I also use on my lap, the sofa, my bed, etc. which is why I bought a laptop. If I wanted something that would only be used at a desk or table I would have gotten an iMac.
Specs:
2.3 GHz quad-core 10th generation Intel Core i7 processor, Turbo Boost up to 4.1GHz
Intel Iris Plus Graphics
16GB 3733MHz LPDDR4X memory
1TB SSD Storage
13 inch Retina display with True Tone
Four thunderbolt 3 ports
Touch Bar and Touch ID
Backlit magic keyboard
I'd love if there was an answer for me if this temp is normal, no fan running normal (pretty sure it isn't, I had a MacBook Air previously) and if not would like a fix or another model.