Whenever I start typing to add code, my Mac fan comes on

I downloaded and applied the update today to 2017.1. Now, as I'm trying to code, whenever I type more than a trivial amount of text, I soon find my cooling fan spinning and my lap burning from the bottom of my MacBook Pro. It's interfering with my getting any work done. It did not do this prior to the update. This is very annoying. Please help.

Update: watching ActivityMonitor while typing random chars at a normal touch typing rate, the CPU usage is hitting 200%, and the fan starts to come on soon after that.

Update 2: power save mode does stop the heat up mostly, however it's unusable in this mode. I'm getting all kinds of editor warnings in commented-out code.