Straight answer: the biggest loss in most cold storage isn't theft — it's a door left open too long. A camera at the cold room entrance, paired with a rule that measures how long the door stays open rather than just whether it opened, catches this before the temperature swing turns into wasted stock. A basic magnetic door sensor does the open/shut part on its own; the camera is worth adding when you also need to see who left it that way.
Ask a cold storage manager what they lost last month and you'll usually get a theft answer, because theft is the loss people go looking for. Ask what the temperature log showed on the days output was down, and you often get a longer pause. Nobody was watching the door.
Why is a door left open a bigger problem than a break-in?
Because it happens constantly and quietly, not occasionally and loudly. A loading dock door propped open during a slow unload, a chamber door left ajar because someone went to fetch a trolley, a night-shift worker who didn't latch it properly on the way out — none of these look like an incident. They look like Tuesday. Multiply a small temperature spike by however many times a week it happens, and it adds up to more damaged stock than most thefts ever cause, without a single alarm going off.
How does a camera actually catch this?
Not by recognising a "door open" event the way a person would glance at it. The mechanism is dwell time. A camera pointed at the doorway feeds a simple motion or state-change model that tracks how long the door has been in the open position, not just that it moved. A forklift passing through for twenty seconds doesn't trigger anything — that's normal traffic. A door still open at the twelve-minute mark during a supposed five-minute unload does, and someone gets a WhatsApp alert while it's still fixable, not the next morning when the batch is already warm.
Do cameras even survive inside a cold room?
This is the honest constraint most vendors skip. A standard indoor camera moved between a warm anteroom and a sub-zero chamber fogs up from condensation the same way your glasses do, and cheap connectors and cabling become brittle in continuous cold. The fix isn't a smarter model, it's the right hardware: housings rated for the temperature range, and mounting the camera at the doorway looking outward rather than deep inside the freezer, where both the fogging and the cold are worse. Get this placement wrong and the analytics layer is watching a smeared lens.
Is a camera even the right tool, or is a door sensor enough?
For pure open-or-shut detection, a magnetic door sensor is genuinely the better tool — it's cheaper, it works in total darkness, and it doesn't care about condensation. If all you need is "tell me when the door has been open too long," start there.
A camera earns its place on top of that when the question becomes who left it open, or what was happening at the door when it did — a pallet blocking it shut, someone propping it deliberately, product being moved out while it sat open. That's evidence a sensor can't give you, and it's usually the follow-up question once the first dwell alert fires and you want to know why it kept happening.
Where does theft still matter in a cold store?
It does, but usually at different points — the loading bay where cartons change hands, the racking aisles for internal pilferage, and the exit route stock actually leaves by. Those deserve their own coverage. The mistake is treating a cold store like a warehouse with a lower thermostat and pointing every camera at theft, when the door-dwell problem is quietly costing more and nobody is currently measuring it at all.
What should you check first?
Pull your compressor's temperature log for the last month and look for spikes that line up with shift changes, loading windows, or maintenance visits. If you can already explain every spike, your door discipline is fine. If you can't, that gap is where a dwell alert pays for itself before it pays for anything else.
We build camera-based analytics for this, including door-dwell alerts — so weigh that recommendation knowing where our interest sits. It won't fit every site: a chamber with no reliable network link, or one where a sensor already does the job well, doesn't need a camera bolted on for the sake of it.