I have a Phalaenopsis orchid I keep indoors. I have watered it twice in the last 5 days however, this morning I found on one of the leaves a discoloured patch that has become very soft and has split and has started to ooze and is wrinkled. The rest of the leaf is fine as are the other leaves. The last water it had I gave it a good soaking because the weather had turned quite warm and I have been putting the orchid in the warmest place of the house on a windowsill. I have put it in the shade today. Can you please advise what I should do?