How to Pre-Cool and Load a Refrigerated Truck

November 11, 2026

A refrigerated truck is built to hold a temperature, not to fix one. Most cold-chain failures don’t start on the road. They start at the loading bay, where a truck is loaded warm, the airflow gets blocked or the doors stay open too long.

Whether you’re moving fresh produce, dairy, meat or pharmaceuticals, how you load decides whether the cargo arrives in spec. Here’s how to get it right.

Know Your Temperatures Before You Start

Confirm the required temperature range with your customer or product supplier before the truck arrives. As a general guide:

Chilled goods (dairy, fresh meat, ready meals): usually 0 to 5 °C
Frozen goods: −18 °C or colder
Fresh produce: varies widely by product. Some fruit and vegetables are damaged by temperatures that are too cold.

Set the refrigeration unit to the product’s required temperature, not “as cold as it goes”. Over-cooling chilled produce can freeze it, which is as much a rejection as arriving warm.

Step 1: Inspect and Clean the Body

Before pre-cooling, check that the cargo area is:

Clean, dry and free of odours from previous loads
Free of damage to the walls, floor or door seals
Fitted with working door seals and, if available, strip curtains

Moisture left in the body turns to ice once the unit runs, and a damaged seal leaks cold air for the whole trip.

Step 2: Pre-Cool the Truck (the Right Way)

Run the unit with the doors closed until the cargo area reaches the set temperature. Pre-cooling takes the heat out of the walls, floor and air, so the cold load isn’t spent cooling the truck.

One important exception: if you’re loading at a dock without a proper seal, or with the doors open to outside air, switch the unit off while loading. Running the unit with the doors open pulls in warm, humid air. That ices up the evaporator and wastes the pre-cool you just did.

Step 3: Make Sure the Product Is Already at Temperature

This is the most common mistake. A refrigeration unit on a delivery truck maintains temperature; it isn’t designed to pull warm product down to spec. Before loading:

Check product core temperatures with a probe, not just the air in the cold room
Record the readings at loading
Refuse to load anything that’s out of range, because once it’s on the truck it becomes your problem

Step 4: Load for Airflow

Cold air has to circulate around the load to keep all of it at temperature. Block that flow and you get warm spots, usually at the back and in the middle of the load.

Keep the front clear. Don’t stack against the refrigeration unit’s air return at the front bulkhead.
Leave space at the top. Don’t load to the ceiling, because cold air travels along the roof to reach the back of the load.
Use pallets. They lift the load off the floor so air can flow underneath.
Keep off the walls. A small gap between the load and the side walls lets air move around it.
Load tight, but don’t wrap airtight. Cover and stretch-wrap on the pallets can trap heat in chilled produce. Follow the product’s packaging guidance.

Step 5: Load in Drop Order

Every time the doors open on a delivery route, warm air rushes in. Plan the load so the last drop goes in first and the first drop sits nearest the doors. Then each stop is a quick open-and-close, not a search through the load with the doors wide open.

Step 6: Don’t Mix Incompatible Loads

Don’t carry chilled and frozen goods together in a single-compartment truck, because one of them will be at the wrong temperature.
Some fruit gives off ethylene gas, which ripens or spoils other produce. Check compatibility before combining loads.
Keep raw meat separate from ready-to-eat foods.

Step 7: Choose the Right Unit Mode

Most refrigeration units offer continuous and start-stop (cycle) modes:

Continuous mode keeps air moving all the time. It’s best for fresh produce and chilled goods that need even temperatures.
Start-stop mode saves fuel and suits frozen goods, which hold their temperature well.

Step 8: Close Up Fast and Monitor the Trip

Once loading is finished, close the doors, switch the unit on (if it was off during loading) and confirm it’s pulling back to set point. On the road:

Check the display at every stop
Use a temperature data logger if your customer requires a record
In South African summer heat, park in the shade where you can and keep door openings short, especially on humid coastal runs

Choosing the Right Refrigerated Truck

The right size matters as much as good loading. A truck that’s too big wastes cooling capacity on empty space, and one that’s too small forces you to overpack and block the airflow.

Elite Truck Hire’s refrigerated fleet comes in 1, 4 and 8 ton sizes. For general deliveries alongside your cold-chain work, our truck hire fleet covers everything from panel vans and curtain sides to drop sides and truck tractors.

Call 0860 009 596 or request a quote, and our team will help you match the vehicle to your load. We have branches in Edenvale, Crown Mines, Centurion, Cape Town and Durban.