see, i see the hot water as being smoother, but i dont feel that it has too much to do with the other chemicals getting trapped in the water, not enough of them contact the water due to the fact that your blowing smoke bubbles, as much as the fact that instead of cooling the outside of the bubble with a hot inner core, your lowering the overall temperature of all the smoke, along with adding water vapor to the smoke. Due to the water vapor, your getting less of a hit, but not a very noticeable one.

hot water=good hits.

every so often i still have a cough or two after some hot water rips, but they are usually short lived, and much easier with the hot water. Everyone just needs to try it. The hottest water you get out of your tap works perfect.