Hi guys I have several devices running iOS 9.1 and ever since the update to 9.1, they are all running hot and the battery drains within 1-2h of using the phones. Standby doesn't produce any heat, however using them does and the phones become uncomfortable to use. Calling really sucks because of the heat. Device 1: iPhone 6S (Samsung), setup as new Checking the battery app revels that the Settings app is responsible for 75% of the battery use within the last 24h. Facebook is NOT installed. I reset this phone (wiped), set it up without backup and the issue remains. Device 2: iPhone 6s (TMSC), set up as new, no backup restore Same. Runs hot and drains. Facebook is installed. Does not hold a charge for more than half a few hours. Device 3: iPhone 6, same instance since 2013 Same. Runs hot and drains. Facebook is installed. Does not hold a charge for more than half a few hours. All three devices have just been updated to 9.1, and did not have this problem before. Also, they are on the same carrier which has just enabled wifi calling. Turning Wifi calling on/off has no impact however. I have a Genius Bar appointment, but I fear they are just going to run a diagnostic that comes back normal, I will insist, they might give me a new phone. That phone will likely have the same issues and it doesn't solve device 2&3.