In iOS 10, there is a new bug discovered which causes the iOS devices to freeze due to which it forces the users to restart their device. The bug affects almost every iOS device which is on iOS 10 or on the latest iOS 10.3.2 beta.
The bug is very easy to perform but it is kind of not very common thing that most users will do. To cause the iPhone to freeze, you have to bring the Control Center and then tap on Airdrop and Calculator both at the same time. This bug affects all devices from iPhone 7 to iPhone 6 and older models running on iOS 10. The bug has become public and Apple will soon fix it.
These kind of minor bugs are usuall but come on who will press both the AirDrop and Calculator icon at the same time? This is a very unusual bug and was discovered by mistake but it will be likely fixed.