Temperature in the body and the tumor reflects physiological and pathological conditions. A reliable, contactless, and simplistic measurement system can be used for long-term monitoring of disease progression and therapy response. In this study, miniaturized battery-free wireless chips implanted into growing tumors on small animals were used to capture both basal and tumor temperature dynamics. Three preclinical models: melanoma (B16), breast cancer (4T1), and colon cancer (MC-38), were treated with adoptive T cell transfer, AC-T chemotherapy, and anti-PD-1 immunotherapy respectively. Each model presents a distinctive pattern of temperature history dependent on the tumor characteristic and influenced by the administered therapy. Certain features are associated with positive therapeutic response, for instance the transient reduction of body and tumor temperature following adaptive T cell transfer, the elevation of tumor temperature following chemotherapy, and a steady decline of body temperature following anti-PD-1 therapy. Tracking in vivo thermal activity by cost-effective telemetric sensing has the potential of offering earlier treatment assessment to patients without requiring complex imaging or lab testing. Multi-parametric on-demand monitoring of tumor microenvironment by permanent implants and its integration into health information systems could further advance cancer management and reduce patient burden.