In this work, we study the effect of heat conduction theories pioneered by Green and Naghdi, popularly called thermoelasticity of type Ⅲ, on the stability of laminated Timoshenko beams. Without the structural (interfacial slip) damping or any other forms of damping mechanisms, we establish an exponential stability result depending on the equality of wave velocities of the system. Our work shows that the thermal effect is strong enough to stabilize the system exponentially without any additional internal or boundary dampings. The result extends some of the developments in literature where structural damping (in addition to some internal or boundary dampings) is necessary to bring about exponential stability.