The dependence of the apparent heat capacity obtained from quasi-isothermal temperature-modulated differential scanning calorimetry (TMDSC) experiments and the thermal conductivity is determined for several cases. The relationships are based on the solution of the heat conduction equation which gives the temperature profile in the TMDSC sample. The temperature profile is then used to calculate the sinusoidal heat flow to the sample. We compare our results with those of other researchers. We also show the effect of thermal contact resistance on the results.