Philosophers have long been interested in the thermal system. As noted above, thermal properties are difficult to connect with other tangible features for both spatial and intensity views. On either view, it seems difficult to make sense of the unique structure and bodily role played by our thermoreceptive systems. One possibility for this difficulty may be due to the fact that thermal properties are secondary qualities. A secondary quality is one that (in some manner) crucially depends on our subjective awareness.   primary and secondary qualities). --> The idea is that out in the world there really is no such thing as “hot” and “cold”. Instead, there are only differing amounts of temperature or mean kinetic energy. We feel something much more structured than this through our skin (a fact most keenly developed in Gray 2012). We feel objects as very cold, to cool, and then on to neutral, and only within a fairly narrow total range. After this neutral point, objects take on an entirely different character, and start to feel warm, followed by hot (again, up to a limit). This space of thermal awareness involves a kind of inversion through a neutral point. But this neutral point is unique to human experience; there is no neutral point in the temperature taken objectively. More importantly, the temperatures that we typically feel as neutral depends on the context and especially on the current thermal conditions of our body and sensory surfaces.