This happened to me the first day I had the laptop. I had just transferred all my data from my 2013 MacBook Pro to my new 2020 MacBook Pro. I thought that perhaps the transfer of so much data had caused the heating. This was before I did any Software update.
My laptop got so hot that I was worried that it would cause a fire. So I didn't use it at all to give it time to cool down, then shut it down before going to sleep that night.
I think I called Apple Support the next day. They tried various shutdowns, and said they thought that might solve the issue. But it kept getting hot even after that. I called Apple again and they walked me through a diagnostic test and said the results of the test showed that there were no hardware issues. So they said to try the software update, that should help solve the problem. But it didn't.
The pandemic was in full swing, with all stores shut down. So I couldn't take it in to an Apple Store to have it looked at or to have it replaced. Apple gave me the name of some smaller businesses in my area that might be open and could look at my laptop for me. But I was afraid to take it there for fear that a small company might go bankrupt during the pandemic. And I didn't think it right to take a brand new laptop in for repair.
By the time our stores opened again, I was long past the 14 day mark.
So I keep my laptop on a cake cooling rack, and check it regularly for how hot it is getting. When it gets really hot, I stop work and give it time to cool down.
I do a lot of detailed graphics with it, but while doing graphics will cause it to become warm, it doesn't make it hot. But using Zoom along with a share screen will make it hot. So will reading newspapers on line while having other applications open when I'm researching an article.