Here's the answer, straight from the horses mouth.
Quote:
Hi Jeff!
Thanks for the link...
Although we have exhaustively tested Scratch-Off compounds at low and high
temperatures, (40-50 and above 85), and have had success, we recommend
working temperatures above 65 and less than 80. (Please note all temps are
Fahrenheit). The compounds are a culmination of years of research and are
compromised of fairly complex chemical chains - these chains require
certain temps to work in harmony. The aggregates in them are of a
diminishing return- that is they start out aggressive, needed for defect
removal, and as they are worked they break down into microscopic
"marbles" if you will. These microspheric marbles create a "No Cut" action
helping to finish off the surface leaving little or no swirls - depending
on the experience of the user. To date - this technology is the purest
form of polishing acrylic and polycarbonate surfaces. This process has
maximized performance between 65 and 80 degrees Fahrenheit.
I hope this helps.
Scott
Unquote.