Abstract: A computer-based method of determining a thermal exposure of a product disposed within a shipping container to determine whether a conditioned environment is required for shipping. A shipping route is defined from a first geographic location to a second geographic location. The thermal characteristics of the shipping container are provided, as is a historical weather database. Ambient temperatures, cloud cover and humidity from the historical weather database are retrieved which correspond to the shipping route. A system of mathematical equations are generated to correspond the retrieved ambient temperature to an ambient temperature within the shipping container and to the product temperature. The corresponding product temperature is compared to a thermal exposure profile for the product to determine if the corresponding product temperature is within the thermal exposure profile.