The invention provides methods for treating a portion or treatment zone of a well that include introducing one or more treatment fluids into the well, wherein the one or more treatment fluids include: (i) a first reactant and a second reactant, wherein the first reactant and second reactant are selected for being capable of reacting together in an exothermic chemical reaction, and wherein the first and second reactant are in at least sufficient concentrations in the carrier fluid to generate a theoretical heat of reaction of at least 500 kJ/liter of at least one of the treatment fluids; and (ii) a treatment chemical in at least one of the treatment fluids, wherein the treatment chemical is selected for chemically reacting with a substance of a material in the portion or treatment zone of the well. The exothermic reactants and the treatment chemical can be introduced in a single treatment fluid or in separate treatment fluids.