Not a problem, Ice! I ride in water temps as cold as 45 degrees Fahrenheit. I wear the Thermalution every time I ride in a wetsuit, even when it's not THAT cold. I'm tiny and get cold easily. Even on warmer days, if I'm its cold enough to still need a wetsuit, eventually over time the wind and water will make me start to shiver after a little while. Once that happens, I love not having to stop riding. If I have my Thermalution on, I still have 2 hours of heat that I can turn on to keep me out on the water having fun.
In the coldest months, of course, I wear booties, gloves, and a hood. When air temps are below 50 as well, I will use the suit on Medium heat setting, but other than that, I keep it on low. It helps a ton! I don't think I could go back to a non-heated wetsuit after last winter.