Kalanchoe Flower Wilting. Deadheading or removing the old flowers improves the plants appearance and might encourage it to produce more blooms. But may be your right it might have been because of a sudden change in temperature.
Trim off any dead or wilting flowers at their stems. Normally the plant needs sunlight but with respect to blooming it is a short-day plant the plant blooms when the days are shorter than 11 hours. Kalanchoe wilt when they are deprived of water.
Older varieties might still produce seed resulting in a plant covered with unattractive wilted flowers.
Water your plant only when the top half inch of soil feels completely dry. Use cactus mix to amend the soil if its too heavy. So wilting can be caused by both under and over-watering. For best results keep your kalanchoe in temperatures of 45 to 65 F 7 to 18 C at night and 50 to 70 F 10 to 21 C.