All color chemicals can be "variable temperature", it all depends on what you want to accept as a deviation on your control strip from standard. In the case of Freestyle chemicals, they have worked out the math in regards times and temperatures. Cooler temperatures, longer processing times. There may be some deviation from Kodak standards in chemical make-up, but I'll bet there is not a lot of difference.
PE may have a comment on this...but all modern E-6 and C-41 films are made from hardened emulsions so they can withstand the 100f standard processing temperatures, thus if you do a process that is dramatically lower in temperature you risk the layers of emulsion not developing evenly, thus causing color and density shifts, even with extended processing times. Most amateur images are acceptable if they have a good skin tone, but for pro use, we need neutral highlights and neutral shadows in all cases.
