I lost several baby phals OVERNITE once, when I accidentally let the greenhouse get too cold....I had watered the day before, and the combo hit them like a sledge hammer....crown rot is horrible and fast! sometimes you can save a plant that hasn't gotten it bad yet by dousing it in peroxide.....moral of story, if you have phals, keep your greenhouse WARM! I found 55 degrees to be perfect for all.....good luck!