A surgical vision system for imaging heat capacity and cooling rate of tissue has an infrared source configured to provide infrared light to tissue, the infrared light sufficient to heat tissue, and an infrared camera configured to provide images of tissue at infrared wavelengths. The system also has an image processing system configured to determine, from the infrared images of tissue, a cooling or heating rate at pixels of the images of tissue at infrared wavelengths and to display images derived from the cooling rate at the pixels.