No, it is not possible to use a smartphone as a thermal camera. Thermal cameras detect different levels of infrared light which the human eye cannot see and convert them into visible images. Smartphones don't have this capability because they lack the necessary hardware components such as special sensors and lenses that are required for capturing infrared radiation. There are some apps available that claim to be able to turn your phone into a thermal camera, but these are typically just simulations rather than actual thermal imaging technology.