Help with cutting data out of Plot

Hey guys. I have multiple figures, all of them have 2 plots so that I can compare the tempurature of the hot water and cold water vs time. At some Points the hot water is colder than the hot water. When the cold water is hotter than the cold water I need to cut this data out and then connect the time. Anyone have any ideas?

[KSSV]

You have data in hand or images?