Last year, I planted an orange tree from a seed that i got from a tangerine. That was during the winter. That summer, i put it outside in the sun at about 9 o'clock. I came back about 20 min. later to find that it had begun to wilt. I immediately took it in. The next day at about the same time (both days were about 75 degrees Fahrenheit at the time) i took it out ,but put it in the shade. I would greatly appreciate any input as to what could be wrong with it.