I've heard of this from other people. There is some grower putting this on tags. I don't like the idea at all, especially for phals. I always water my phals with warm water.

Years ago, I heard about watering hanging baskets with ice cubes. I didn't do that either. Maybe it's leftover childhood trauma from when I would get a fever and have to sit in a bathtub of cold water, wrapped in a wet cloth. BRRRRR! To this day, I want to move to the tropics! LOL