# IoT Services for Monitoring Food Supply Chains
## 2 Literature Review
### Temperature and Humidity Control in Cold Chain Logistics  
Monitoring temperature conditions during transport gained popularity in the business sector during the mid-2000s. This shift was marked by the widespread adoption of sophisticated data loggers and monitoring devices, which were integrated into shipments to mitigate risks associated with temperature variations. These technological advancements help ensure compliance with agreed-upon temperature ranges and provide a comprehensive history of temperature conditions throughout transit. The driving forces behind the evolution of temperature monitoring practices included a growing awareness of the potential risks associated with improper temperature management, increased regulatory requirements, and the demand for higher quality assurance standards. As a result, organisations have increasingly recognised the importance of implementing robust temperature monitoring systems to protect their valuable temperature-sensitive products during transportation [4]. The primary rationale for utilising temperature and humidity monitoring devices is the critical need for continuous and real-time tracking of these environmental conditions. This vigilance is vital for determining whether the integrity and quality of temperature-sensitive products are at risk due to exposure to unfavourable or undesirable environmental factors. When selecting a monitoring device, it is essential to consider the user's specific needs, which will determine whether an active or passive system is suitable. Based on the unique requirements of the product in question, the selected device (or sensors) can play a significant role in either approving or rejecting shipments. The nature of the information gathered by these sensors can vary significantly, as it is greatly influenced by the specific application for which the sensors are designed and the particular technology used in their operation. This nuanced selection process ensures that the monitoring systems are tailored to meet the specific operational demands and quality assurance standards necessary for efficiently handling sensitive products [11]. It is imperative to maintain a specific low-temperature range and appropriate relative humidity to preserve the quality and integrity of perishable goods. Additionally, some products require even more extreme conditions, often referred to as ultralow temperature storage or deep freeze environments, to ensure their viability and safety. If the appropriate temperature is not consistently upheld throughout the storage and transportation processes, it can result in significant product degradation. This compromise affects the quality of the goods and can lead to substantial financial repercussions for businesses, as spoilt products may have to be discarded or result in customer dissatisfaction. Therefore, strict adherence to temperature and humidity control protocols is crucial in handling perishable items to avoid adverse outcomes [12]. The temperature standards applicable to cold chain logistics can differ significantly based on the specific type of product being transported or stored. Regulatory authorities and industry organisations have developed comprehensive guidelines for managing temperature and humidity to ensure the quality and safety of products that are sensitive to temperature fluctuations. These standards ensure that such products remain safe for consumption and retain their intended quality throughout the supply chain. Overall, implementing these temperature standards is vital for effectively managing cold chain logistics, as they play a key role in ensuring that temperature-sensitive products reach their destination in optimal condition and are ready for consumption. Similarly, products like meat, dairy, and seafood must be maintained at temperatures between 0 \({}^{\circ}\)C and 5 \({}^{\circ}\)C during storage and transportation.