How to ship refrigerated products

Shipping refrigerated freight is unforgiving: a few degrees of drift or a few hours of delay can turn a full trailer of perishables into a total loss. The discipline that prevents that is the cold chain — keeping product within its required temperature range at every step from origin to delivery.

Whether you move produce, pharmaceuticals, frozen food or fresh seafood, the same principles apply. Here is how to get refrigerated freight to its destination in the condition it left in.

Before anything else, pin down the exact range your product must stay within. Frozen goods, chilled produce and temperature-controlled pharmaceuticals each have very different windows, and "cold" is not a specification.

• Frozen freight typically ships at 0°F (-18°C) or below.
• Fresh produce and dairy usually run between 33°F and 41°F (0.5°C–5°C).
• Pharmaceuticals and biologics often require a tight 36°F–46°F (2°C–8°C) window with documentation.

Document the required range on the bill of lading so the carrier sets the reefer correctly and there is no ambiguity in transit.

A refrigerated trailer ("reefer") is not just an insulated box — it is an active climate system. Match the equipment to the load: a multi-temp reefer can carry frozen and chilled product in separate zones, while a single-temp unit suits one consistent setpoint.

Confirm the reefer is pre-cooled before loading. Loading warm product into a warm trailer and expecting the unit to "catch up" is one of the most common cold-chain failures.

Good packing supports the reefer, it does not replace it. Air must circulate around the load for the unit to hold temperature evenly.

1. Pre-cool the product to its target temperature before it ever reaches the trailer.
2. Palletize so air can flow — leave channels around and over the load, and never block the unit’s air chute.
3. Use insulated packaging or gel packs for short, sensitive legs or last-mile handoffs.
4. Load quickly to minimize the time the doors are open and warm air is entering.

What you cannot measure, you cannot defend. Temperature loggers or telematics give you a record of the trailer’s performance for the whole trip — proof for the receiver and protection if a claim arises.

Build in buffer time, too. A tight delivery window with no slack means a single traffic delay can push product out of spec. Plan the lane so the reefer keeps running on schedule.