We study theoretically how energy and heat are transferred between the two-dimensional layers of bilayer carrier systems due to the near-field interlayer carrier interaction. We derive the general expressions for interlayer heat transfer and thermal conductance. Approximation formulae and detailed calculations for semiconductor- and graphene-based bilayers are presented. Our calculations for GaAs, Si and graphene bilayers show that the interlayer heat transfer can exceed the electron–phonon heat transfer below the (system-dependent) finite crossover temperature. We show that disorder strongly enhances the interlayer heat transport and pushes the threshold toward higher temperatures.