Abstract A low‐cost microfluidic platform integrated with a flexible heater was developed for in situ temperature‐dependent spectroscopic measurement at the point of care. After verifying the system by comparing on‐chip spectroscopic measurement of methylene blue with the conventional spectroscopy, we demonstrated its applications in temperature‐dependent absorption spectroscopy of a model biomolecule, curcumin. The system is portable, battery‐powered and requires ultra‐low volumes of analytes, which is highly suitable for point‐of‐care characterization.