For those struggling with issues like >85degC CPU which sits on 15% utilization constantly – one full core, <2hr battery life and occasional beachballs despite 8GB/6G SSD, the culprit could be Backblaze causing Spotlight indexer (mds and mdsworker) to go nuts.

Add /Library/Backblaze to the Privacy tab in the Spotlight System Preferences GUI. Problem solved (for me, this change instantly halved my CPU temp, doubled battery life and dropped CPU utilization by 80%).

Note that this doesn’t effect your Backblaze functionality, it merely disables Spotlight from constantly indexing the Backblaze index of your disk (wee loops). If you don’t have Backblaze, obviously this fix is not for you, but another application could be the culprit (mds / mdsworker = Spotlight indexing, go forth and Google!).