What are the symptoms of water damage?

Hi, recently i had accidentally spilled a whole cup of ice green tea latte on my iPhone. I immediately cleaned off as much liquid as i could and the iphone seemed to be functioning fine. ( For the next 4 hours)

However, after charging the phone and unplugging it, it suddenly became very hot(approx 60 degrees celcius) and the battery drained extremely quickly. I was watching the phone and it was dropping 1% perhaps every 20 seconds. I had made sure to turn off all back ground tasks, wifi and 3g, but it was still getting very hot.

Even after turning off the phone, the bottom left area of the phone stayed at the same temperature for about 1 hour, which is really making me concerned.

Could the liquid have somehow screwed up the battery and caused it to drain and produce lots of heat very quickly?