District heating and cooling networks (DHCs) utilize excess heat generated from power generation and other industrial processes to heat/cool fluid at a central location, and then circulate it through a network of pipes and heat exchangers to meet the heating/cooling needs of residential and commercial buildings. Therefore, this excess heat must be distributed carefully to ensure fairness in the energy sharing among the buildings, or in the thermal discomfort suffered by the building occupants. In this presentation, we will present an overview of our recent work on ensuring thermal fairness between buildings in a DHC network through demand response (DR) mechanisms. Despite the complexity of the heat exchange equations, we show that the optimal controls (such as thermostat settings, water flow rates, or supply water temperature) can be computed exactly in low computational complexity. We demonstrate the convergence of the controls to the optimal indoor temperatures and fluid flows.