In collaboration with Dr. Amir Hajrasouliha at IU Health, we use nanodiomonds (ND) hosting nitrogen vacancy centers (NVs) as a probe of temperature inside live cells. The optical detection of magnetic resonance (ODMR) enables determination of a shift in the NV spin transition induced by change in the temperature around the ND. The approach enables precise determination of temeprature in live cells with high spatial resolution.