A cool bag's performance is not determined by plate position alone. Assess the product requirement, bag model, load and actual route together.
Record product temperature and bag condition before dispatch. Follow the maker's instructions for coolant type, preparation and placement; separately check whether direct product contact is suitable.
For a trial route, place a logger in the same compartment as the product. Record departure and arrival times, stops, lid openings and the arrival reading. One air reading does not replace product temperature.
If the result misses the target, review route duration, waiting, lid openings, load density and coolant arrangement first. Change one factor at a time and measure again on the same route with a comparable load.
Keep the trial record with bag model, serial number, product and weather conditions. Do not assume the result transfers to another bag, load or route.