I installed chrome for the sole purpose of using its built-in flash player for streaming webpages that require flash. I noticed that after a while, my mbp heats up quite a bit and about 1 min after i quit chrome, it cools back down to normal.
It happened to me too when playing flash videos with chrome in some places. I believe, and from what I've searched on the internet this is due to the flash that chrome comes preloaded with. If you check out the activity monitor whilst using chrome and watching flash when heating quite significantly you'll see is that the "pepperflashplayer" that comes with chrome is using upwards of 150% cpu power.
I've seen that it varies website to website, must have something with their implementation of flash or something (I'm guessing).