Setting a reefer to the wrong temperature is one of the most expensive small mistakes in freight. A few degrees separates delivered product from a rejected load, and “keep it cold” is not a spec. This guide covers standard setpoints by commodity group, the settings that matter beyond temperature, and how to write a BOL that protects you when the trailer doors open.
Frozen: 0°F and below
General frozen foods ride at 0°F (-18°C) or colder. Ice cream is stricter — -10°F (-23°C) — because it shows heat abuse faster than almost anything else; even brief warming causes texture damage that is obvious at destination. Frozen seafood and meats also commonly spec -10°F. Frozen loads are the most forgiving of cycle-mode operation, but they are unforgiving of warm loading: a trailer must be pre-cooled and product loaded already frozen — a reefer maintains temperature, it does not blast-freeze warm product.
Refrigerated: the 33-41°F band
Fresh meat, poultry, seafood, dairy, and eggs ride at 33-36°F, close to freezing without crossing it. Most vegetables, berries, grapes, and stone fruit spec 32-36°F. Milk and fresh juice typically run 34-38°F. Pharmaceuticals under cold chain rules ride 36-46°F (2-8°C) with tighter documentation — see our guide to cold chain warehousing in Miami for the storage side of that spec.
The chilling-sensitive exceptions
The counterintuitive group: commodities damaged by temperatures well above freezing. Bananas ride at 56-58°F — colder and they gray and never ripen. Tomatoes spec 55-60°F depending on ripeness, cucumbers and peppers 45-55°F, citrus generally 38-48°F by variety, avocados 40-55°F by ripeness stage. Tropical fruit, basil, and orchids all have their own floors. When a mixed produce load must share one trailer, the warmest requirement wins, and ethylene compatibility matters too: ethylene producers like bananas and avocados should not share air with ethylene-sensitive lettuce, broccoli, or flowers on long hauls.
Non-food freight that rides refrigerated
Plenty of dry freight specs temperature protection, especially in Florida, where summer trailer interiors exceed 130°F. Chocolate and confectionery ride 55-65°F; wine ships at 55-60°F to avoid cooked flavors (our wine and spirits logistics guide covers this in depth); cosmetics, candles, adhesives, paints, and many nutraceuticals all have melt or separation points a Florida summer will find. If your product has ever arrived “a little soft” in August, it needs a setpoint, not hope.
Settings beyond the setpoint
Three more decisions ride on the work order. Mode: continuous for produce, pharma, and anything sensitive; cycle-sentry only for hardy frozen goods where fuel savings outweigh temperature swing. Fresh-air exchange: open vents for respiring produce on multi-day hauls, closed for frozen and packaged goods. Loading pattern: center-loaded pallets with air channels along walls and floor, never blocking the return-air chute — airflow, not the thermostat, is what actually keeps the back of the trailer cold.
Write the spec, then verify it
Put the setpoint, mode, and vent position on the BOL; require a pre-cool to setpoint before loading; pulp product at loading and note temperatures on the paperwork; and use trailers with download-capable data recorders so disputes are settled by the unit’s own log. Go Freight’s refrigerated fleet runs South Florida and nationwide lanes with live temperature telemetry through TruckHub, so you see the setpoint holding in real time instead of finding out at delivery. Moving temperature-sensitive freight out of Miami? Get a reefer quote with the spec built in.
Frequently asked questions
What temperature should a reefer be set at for frozen food?
0°F (-18°C) or colder for general frozen food, and -10°F (-23°C) for ice cream and similar sensitive frozen products. Always confirm the shipper’s spec — the BOL temperature governs the move.
What is the difference between continuous and start-stop reefer mode?
Continuous mode runs the refrigeration unit constantly for tight temperature control and air circulation; start-stop (cycle-sentry) cycles the unit on and off to save fuel, allowing wider temperature swings. Produce, pharma, and anything sensitive should run continuous; hardy frozen goods often tolerate cycle mode.
Can one reefer carry products needing different temperatures?
Only with a multi-temperature unit and moveable bulkheads dividing the trailer into zones — common in foodservice distribution. In a standard single-zone reefer, everything rides at one setpoint, so mixed loads must share a compatible temperature and, for produce, compatible ethylene sensitivity.