Magnetic core–shell nanoparticles are one of the most interesting nanocarriers. Smart polymers can be attached to nanoparticles as a suitable shell. Cancer tissues, with higher temperature than normal one, are one of the best targets for these systems in which the polymeric shell shrinks and thus drugs are released. The aim of this research is to synthesize such a smart nanocarrier with a thermoresponsive shell. Magnetic nanoparticles are coated with poly(N‐isopropylacrylamide). Afterward, the as prepared nanoparticles are analyzed through different characterization methods (scanning electron microscope, Fourier‐transform infrared spectroscopy, carbon–hydrogen–nitrogen–sulfur elemental analysis, energy‐dispersive X‐ray spectroscopy) and their response to the temperature is investigated in different temperatures (37 and 40 °C). Results demonstrate that a biocompatible nanocarrier with the average size of about 35 nm and 83% entrapment efficiency for curcumin is successfully synthesized. The drug release process shows a controlled behavior over temperature. It has an increasing trend by increasing the temperature from 4 to 37 °C and then to 40 °C. Moreover, the cytotoxicity of drug loaded nanocarrier is obviously increased at 40 °C compared to 37 °C. It can be concluded that this new smart nanotheranostics agent can be successfully applied for cancer treatment.