Fans are running at ~50% since I turned my MBP on this morning and this is a snapshot of the CPU use, it's crazy for 40 tabs open (I often have >100 tabs with several devoted to thread hungry social media sites like twitter and facebook).
As pointed out by @Tetsujin the Chrome Helper process at the head of the lists had "gone crazy" and was consuming all spare CPU cycles. Double clicking it and quitting it did the trick.
I had a similar problem with fans and battery death, and solved it by removing Gmail Offline from Chrome. It was going CRAZY whenever Chrome was running. You can remove it by opening Chrome Apps (the grid of 9 dots in the top left corner of Chrome), right click on the Gmail Offline icon, and Remove it. Much better