The iPhone comes with a hidden sensor, which you need to keep an eye on. Check your iPhone now to check if the hidden sensor is red as you may have a huge problem.
When your iPhone is damaged by water this sensor turns red. A good warning sign that will allow you to know if you have recently spilled a drink and your phone’s being a bit buggy.
Most of the recent iPhones and iPads models come with Liquid Contact Indicators (LCI). The handy sensor is present in all iPhone 5 onwards models, you can find it where the SIM card is stored.The sensor remains white or silver which indicates your device has no water damage issues. All you need to do is remove the SIM card tray and take a look at it.
According to Apple, using a lighted magnifying glass and angling the light to get a glimpse would prove to be handy.