Battery-free wireless temperature sensors can help food and beverage businesses automate refrigerator temperature monitoring, improve compliance, reduce manual checks, and cut food and energy waste. It focuses on use cases in coffee shops, food outlets, and retail refrigeration, including a proof of concept across 50 stores where sensors transmitted temperature readings every one to two seconds through Bluetooth gateways into a hosted IoT platform. The paper presents indoor light harvesting as a way to remove battery maintenance while giving store managers and head office teams live dashboards and alerts when temperatures move outside compliant ranges.