We investigate the Cauchy problem for the thermoelastic plate system associated with Newton’s law of cooling, where optimal growth ( n ⩽ 4 n\leqslant 4 ) or decay ( n ⩾ 5 n\geqslant 5 ) estimates and asymptotic profiles of solutions for large-time are studied. Especially, the additional lower-order term in the temperature equation weakens decay rates of the vertical displacement, and leads to a new leading term comparing with the classical thermoelastic plates.