We’ve seen numerous instances of people spilling water on their phones or dropping them in the pool by accident. Water can induce short circuits in the phone, which can result in the phone being bricked.
In this situation, the best plan of action is to turn off your phone right away. Some Samsung, LG, and HTC phones allow you to remove the back of the phone and pull out the battery, but this is not possible with iPhones due to their non-removable batteries. Taking your phone to an iPhone repair shop is the best option.