FrostAlert

Refrigerators play a crucial role in preserving perishable goods such as food, vaccines, and biological materials. However, many users are unaware of temperature fluctuations that may compromise the safety and integrity of stored items. Studies have shown that foodborne pathogens such as Listeria monocytogenes and Salmonella spp. can thrive under mildly abusive refrigeration conditions, leading to serious health risks. In medical settings, even slight temperature deviations in vaccine storage can lead to compromised efficacy, potentially triggering widespread health emergencies. Despite 87.2% of users being aware of the optimal temperature range (1°C to 5°C), few regularly monitor refrigerator performance or are equipped to detect malfunctions in real-time. To address this issue, a real-time monitoring system, FrostAlert, was developed. FrostAlert uses a DHT-22 temperature sensor and an ESP-32 microcontroller to continuously collect and analyze temperature data. When the internal temperature exceeds or falls below the predefined threshold of −10°C to 10°C, the system sends automated alerts to users via Gmail—chosen for its widespread accessibility and ease of integration. A user-friendly web interface was developed to display sensor readings, track anomalies, and record alert history. Experimental results demonstrated that FrostAlert reliably detects temperature abnormalities and notifies users within one minute, minimizing the risk of damage or contamination. With its low cost, ease of deployment, and adaptability to both domestic and medical settings, FrostAlert presents strong commercialization potential for households, vaccine storage centers, cold-chain logistics, and food safety management. This system represents a proactive, scalable solution to a long-standing safety challenge in cold storage environments.