A refrigerated trailer is the best protection there is against cold. On Canada–US lanes in winter, freight that would ride a dry van in July often needs a reefer running in heat mode. A pallet of bottled beverages, a load of latex paint or a trailer of potatoes can be ruined by a single night parked in a yard at −20 °C. Protect-from-freeze service exists for that night.
In short
- A reefer heats as well as cools. For freeze-sensitive freight in winter, it is the only reliable protection over a long run.
- Much freight is damaged at temperatures well above the lane’s lows: beverages, water-based coatings and many foods.
- Pre-heat the trailer, load from a heated dock, run the unit continuously, and never leave the trailer unpowered.
What freezes, and what freezing does
| Freight | Risk |
|---|---|
| Bottled water, soft drinks, juice | Freezes around 0 °C (32 °F); containers burst and leak |
| Beer and wine | Alcohol lowers the freezing point only a few degrees |
| Latex paints, stains, adhesives, caulking | Freeze–thaw cycles ruin consistency for good |
| Potatoes, apples, onions | Frozen tissue turns soft and discoloured |
| Cosmetics, emulsions, some medicines | Separate or degrade; follow the label’s storage range |
Many of these products carry a “protect from freezing” or “keep above” instruction on the case. That instruction is the shipper’s temperature specification, and it belongs on the bill of lading.
Why a dry van isn’t enough
An unheated trailer’s interior follows the outside air over a long run. On Ontario and Great Lakes lanes in January, overnight lows below −15 °C are common, and a trailer parked overnight at a receiver or a truck stop spends its coldest hours with no heat at all. Thermal blankets slow the loss for a short, direct run but can’t stop it. For anything longer than a same-day delivery, freeze-sensitive freight belongs in a heated trailer.
Running a reefer in heat mode
The refrigeration unit on a reefer trailer heats as well as cools, and holds a setpoint whatever the weather outside. Done properly, protect-from-freeze service looks like this:
- A setpoint safely above freezing. Many shippers specify somewhere around 4–10 °C (40–50 °F), but the product’s label and the shipper’s written specification decide.
- A pre-heated trailer. Cold walls and a frozen floor chill the bottom tier of pallets before the unit catches up. Bring the empty trailer up to setpoint before loading.
- A heated dock. Freight that has already sat on an unheated dock for an hour starts the trip cold.
- Continuous operation for sensitive loads in deep cold, so the unit doesn’t sit idle long enough for the trailer to drift.
- Fuel and power. The unit runs on its own tank, and a reefer that runs dry overnight protects nothing. Dispatch should watch fuel and temperature remotely, and a loaded trailer should never sit unpowered in a yard.
Plan the lane, not just the trailer
Winter adds hours, and hours are when freight is exposed:
- Know the snowbelts. Lake-effect snow around London, Ontario, and south of Buffalo can close highways with little warning.
- Avoid weekend yard time. Ship early in the week, so a delay doesn’t strand freight in a cold yard over a weekend.
- Check receiver hours. A trailer that arrives after the dock closes waits outside overnight. Make sure it waits under power, or deliver the next morning.
- Book early in the season. From November, freight that rode dry vans all summer competes for the same reefers as holiday food, as we covered in our Q4 peak season guide.
What to put in writing
The bill of lading for a protect-from-freeze load should state: Protect from freeze, the setpoint in °C and °F, continuous operation where required, the product temperature at loading, and any receiver instructions for after-hours arrival. If the load is food, the temperature specification also does the job our FSMA guide describes.
How Alpha Trans runs winter loads
Our multi-temp reefers run from −20 °F to 70 °F, so the same trailer that hauls frozen product in July can hold beverages above freezing in January. Every unit logs temperature continuously and alerts our 24/7 dispatch desk the moment a load drifts. A full temperature printout travels with the freight. Our tractors are maintained in our own Brampton shop on a 15,000 km cycle, so the fleet reaches winter in shape for it. Our refrigerated trucking service covers how we run temperature-controlled freight in every season, and our reefer guide explains how cold chains fail.
One cold night can write off a whole load. Book protect-from-freeze capacity for the season.
Filed under Cold chain
Cover photo: P199 via Wikimedia Commons , CC BY-SA 3.0
