Insulated boxes equipped with Phase Change Material (PCM) are primarily used for the last mile food delivery, as they are simple to use and low-cost. However, these boxes maintain high average temperature and significant temperature heterogeneity in transport. This work presents a numerical study to predict the heat transfer and airflow inside an insulated box (overall heat transfer coefficient 0.9 W‧m-2 ‧K-1) equipped with PCM (ice, melting point 0°C). Three configurations were studied: an empty box, a box loaded with Extruded Polystyrene (XPS slabs), and a box loaded with test product (Tylose slabs). Computational Fluid Dynamic simulations were performed by ANSYS FLUENT. The numerical results of temperature and velocity fields were compared with experimental values measured by thermocouples and Particle Image Velocimetry, respectively. Good agreement was obtained between the numerical and experimental results, with the maximum difference of 1.5°C and 0.03 m•s-1 .