Cold-chain logistics demand precise temperature monitoring to ensure the safety and quality of perishable goods during transport. Conventional solutions rely on battery-powered temperature loggers, which contribute significantly to electronic waste due to limited reusability. This thesis addresses this environmental concern by contributing to the development of a fully batteryless, wireless temperature logger designed for long-duration cold-chain monitoring. Focusing on the sensing and data logging subsystem, this work presents the design and implementation of an ultra-low-power system capable of accurate temperature readout and multi-week data storage under strict energy constraints. The system integrates a microwatt-level temperature sensor, a power-optimized microcontroller, and energyefficient logging strategies to balance measurement accuracy, memory use, and power consumption. The final implementation is shown to have an idle power draw of <1μW and an energy use of 14μJ over the measurement and storage period, with a peak power of 411μW . The temperature measurements were found to be accurate within ±0.5°C . This accuracy and energy efficiency, demonstrates its potential as a sustainable alternative to traditional battery-powered loggers