Don't really see any advantage or disadvantage with either hot or cold. One thing I might mention, without the intent to hijack this thread, is that ready mixed PCP tends to be extremely expensive. My understanding is that there are resources where you can buy PCP in quanity, such as pints, quarts, etc., and add distilled water to make your own for a fraction of the costs. Unfortunately, any pharmacist I have ever broached the subject with has no real idea what I am talking about. Has anyone established a resource to buy PCP in bulk?