I also updated to iOS 14.0 and it was all good on my iPhone 6s, no issues. The problems started after I installed 14.0.1 . Now my iPhone 6S has problems with high temperatures while using bluetooth and wifi connectivity. It is practically unusable since the update because of the overheating. The only time I have no problems with overheating is while using mobile data/transfer. Every time I turn on the bluetooth or wifi the iPhone goes extremely hot. I have tried everything : resetting the phone to factory, setting up as new, etc. Nothing works. As soon as I turn the wifi or bluetooth on the phone gets painfully and dangerously hot. Of course while getting really hot the battery drops within minutes. I am afraid those high temperatures could damage my phone, the board and battery (it is 87% now, before the update was 89% ). I am disappointed as I really like my 6s and was going to use this phone for some time more. I actually need two mobiles and was waiting for iPhone 12. But as 6s was unusable also during phonecalls (also overheating) I had to buy another phone (SE 2020 ). I didn't update it to 14 as I was afraid it could affect the new phone but in consequences I can't use my Apple Watch 5 as SE is not up to date and I can't use it with 6s because it gets hot within seconds I turn on bluetooth and wifi. This is just sad.