To the best of my knowledge, thermal imaging (with a thermograph as the end results) is performed using arrays of thermopiles. This can become hugely expensive and is the reason fire services sometimes have trouble affording thermal imaging cameras. Snakes have heat sensitive ion channels that work with their brain to allow them to "see" infrared light overlayed with vision from their eyes. Would it be possible to produce heat sensitive ion channels, and design systems to produce images from them? Would it be cheaper?