In the present work, the thermal behavior of a thin slab under the effect of a fluctuating surface thermal disturbance, as described by the dual-phase-lag heat conduction model, is investigated. It is found that using the dual-phase-lag heat conduction model is essential at large frequencies of the surface disturbance. Mathematical criteria that specify the limits beyond which both the hyperbolic wave and the dual-phase-lag heat conduction models deviate from the diffusion model are derived.