Record Heat Puts Cold Chain Shippers on Alert

Posted by Harriet Mills on Jul 16, 2021 3:16:26 PM

Shipping temperature-controlled freight can be a risky business even on the best of days, but when outside temperatures soar to record-breaking highs, (most recently putting 13 million Americans under a severe heat advisory), it is time to pay extra attention to your cold freight shipments.

The past month was the hottest June in North America on record. In recent days, California, Nevada, and Arizona all surpassed previous record temperatures. It has been so hot in the Pacific Northwest that roads are actually buckling. What does this mean for shippers and carriers?

If you are a truck driver, it means you need to closely monitor your reefer unit and the inside temperatures of the trailer to protect it from the intense outside heat. Sustained high temperatures can be extremely hard on a reefer unit, and if regular maintenance has not been done on the equipment, failures are likely to occur.


If you are a shipper, you may want to include some type of temp-recording device inside the load that relays or saves information for you or your 3PL freight provider. Older reefer units may only have the temperature download information on the unit itself, but some shippers prefer to rely on a secondary monitoring system that rests on or within the product, called a temptale recorder. Temptales, like newer reefer units, also provide real-time information so that if the cargo experiences a temperature change, the dispatcher or fleet operator is alerted.


Maintaining the cold chain comes with a lot of responsibility. Necessary preparation involves protocols for packaging, staging, and pre-cooling. There also is required documentation to prepare, FSMA compliance rules to follow, and usually, a list of standard operating procedures to check against that is specific to the type of cold freight being shipped.

Cold Freight Shipping - Preparation is Everything

When things go wrong, the big question is, who is responsible for what? Regarding the truck, the responsibility falls on the driver/carrier for having their equipment serviced regularly and for checking the reefer unit and trailer for leaks and malfunctions before loading.

Less than a decade ago things were much different. For example, a typical shipment of frozen fish would leave a dock in California and possibly go through several different states and several different temperature zones before arriving at its destination. It also may have had several deliveries along the way. The shipper knew it was frozen when it left its place of origin, and the receiver made a notation that it was frozen upon arrival at its destination.

But what about the four hours it sat in an open truck while other cargo was being unloaded on a hot 102° Fahrenheit day in the Southwest? Before GPS tracking and real-time visibility, there was no way of knowing what happened in between points A, B, C, and D.

Protecting Perishable Foods During Transport by Truck and Rail (USDA Handbook) 

Today, technology allows us to keep an eye on the movement and condition of every shipment. We now have the visibility to know where the truck is in real time as well as the temperature of the inside trailer. This information is captured by either the reefer unit on the trailer or the temperature monitoring device (TMD) attached on or near the product on board. 

The beauty of this transparency is that everything can now be documented and recorded. Reefer units have downloadable information, and the sensor readings on TMDs can be captured by photo or signed off on by dock masters or drivers.

To learn more about keeping your cargo cold this summer, download our free guide to maintaining the cold chain.


Tags: Cold LTL, refrigerated freight services, truckload freight shipping