Dhund is a 1973 Hindi movie produced and directed by B. R. Chopra. The film is based on Agatha Christie's play, The Unexpected Guest, and stars Sanjay Khan, his then flame Zeenat Aman, Danny Denzongpa, Deven Verma, Madan Puri, Navin Nischol and Ashok Kumar.
The heat equation is a parabolic partial differential equation that describes the distribution of heat (or variation in temperature) in a given region over time.
In the case of liquids and solids there is also potential energy (of interaction of atoms) involved, and so on. A heat is defined as a transfer (flow) of thermal energy across certain boundary (for example, from a hot body to cold via the area of their contact).