http://www.ebay.com/itm/Titanium-Hea...item2a22418b3a

Yes that is what I do in my cold basement. i have one similar to this in that the entire heating element is submersed and can lay flat while the controls are left out. I use an over sized tray under my developer tray and heat a water bath or sometimes I just put the heater into the developer. In both cases you have to rock the tray a lot to spread the heat.