iPhone often freezes nowadays Is there a reason why nowadays, even in warm conditions, my iPhone freezes and restarts? 

By this I mean it freezes for a while and then restarts into a black screen for 10-20 secs followed by the Apple logo and then the Home screen. This can happen when taking pictures, starting an app, or just opening a link in Safari. It seems to be a software problem and only started this year.

I've tried:


Updating iOS to 11.2.2
Taking it in for checking - the battery was replaced and they said the logic board was ok.




It's an iPhone 5s running iOS 11.2.2.
The term &quot;freezing&quot; here should not be interpreted literally. Freezing simply means that the display stops updating, audio stops playing or similar (i.e. nothing is happening) - it doesn't have anything to do with hot or cold environments.
The behavior you're seeing sounds like a hardware defect.
You mentioned already having tried upgrading iOS. I would take a backup of the phone, and then do a complete restore of the iOS software - erasing all contents and settings on the phone. If it still freezes afterwards, it is most probably a hardware problem.