It is known that conditions such as inflammations, heart attacks, brain seizures and cancer are accompanied by hyperlocal temperature changes in the affected tissues. Therefore, temperature measurements are of immense importance for diagnostic purposes,. Temperature in biological systems can be measured using non-contact luminescence thermometry. Progress in the field of luminescence thermometry has been rapid, however challenges still remain, such as developing multifunctional materials and materials that are non toxic to the human body. In this project we will develop water soluble K3ZrF7:Tm3+ nanoparticles as nanothermometers. They will be wrapped with thermoresponsive drug-releasing polymers, forming hybrid nanotheranostic materials. The thermoresponsive polymers will be used to covalently attach a drug - doxorubicin - that is only released after internalization in cells upon application of a mild temperature trigger, induced by photothermal heating. Such hybrid systems can be used for combined temperature detection (to locate cancer cells), photothermal therapy and drug release (to fight cancer cells) extending the possibilities of combining thermometry with anticancer therapies.