It’s a larger and cellular connected version of technology that hospitals employ to ensure that medicines are kept within mandated temperature ranges and is even used in some restaurant fridges. The benefits are pretty obvious. When the temperature drops near a problematic level, operators get a warning, and when it goes above that level they get a series ever-increasing alerts. These alerts are also documented in a computer system, creating a record that can be provided in case of an audit.

In hospitals and restaurants fridges are easy to access and fix, but on a ship where refrigerated containers are stacked they may be hard to get to, I’m not sure what a remedy might be in case of an alert. At least there is a record that will show that they goods inside went out of the set temperature range and might be unsafe or damaged.

The AT&T system for Maersk uses a device that contains a cellular SIM card that communicates over the 3G network and is capable of working in high temperatures. It also contains a GPS unit, a ZigBee radio and antenna, as well as multiple interfaces for connecting into the refrigerated container’s controller. The AT&T (T) device can operate with two-way connectivity from just about anywhere in the world. A secondary benefit is that if the container goes astray it could be tracked.

Containers tend to fall of into the ocean during big storms and there is a surprising amount of undocumented loss associated with accidents like that. Having a GPS device on them will help solve that. With this deployment, the staff that once manually checked containers can now glance at a computer screen to ensure containers are cooled and working properly.

For more on the Internet of things check out this Fortune video:

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