With orchids, patience is a virtue. Keep an eye on them and see if any other leaves start to wilt. If another one starts to get droopy, then it's time to check the roots. I would also take the time to wipe the leaves with a cloth dipped in "clean" water - bottle water from the store, RO or distilled. About every 5 days or so. This will help eliminate chemical build up. Don't get the leaves soaking, wet the paper towel, then squeeze out most of the water and wipe the leaves, turning the towel to get a clean surface each time. Wipe the undersides too!!!