A method for sealing a high permeability region in a reservoir is provided. The method includes injecting a gel precursor solution into a high permeability region in a reservoir, injecting a sodium nitrite solution proximate to the high permeability region, and injecting an ammonium chloride solution proximate to the high permeability region. The ammonium chloride solution and the sodium nitrite solution are mixed proximate to the high permeability region. The ammonium chloride solution and the sodium nitrite solution are allowed to react, increasing the temperature of the reservoir proximate to the high permeability region. The gel precursor solution is allowed to react to form a solid gel in the high permeability region.