Drunks are a varied species, and the loud among them are easily picked out in a crowd. But even the more silent sorts may be found out, given away by their hot noses and cool foreheads.

Georgia Koukiou and Vassilis Anastassopoulos, of the University of Patras in Greece, propose that infrared imaging of people’s faces, backed by algorithms that detected facial regions, could be an easy way to test sobriety, Wired reports.

The researchers studied the faces of about 20 volunteers before and after they knocked back four beers. They found that the temperature of the nose was a decent indicator of their subject’s level of inebriation. In all cases, the noses of the beer drinkers were hotter than they were pre-beer. And, more usefully, their noses were almost always hotter than their foreheads. In September they published their findings in the International Journal of Electronic Security and Digital Forensics.

As the theory goes, alcohol in the bloodstream dilates blood vessels, increasing blood flow just under the skin. This heats up certain parts of your face, skewing its otherwise even heat map.

Koukiou and Anastassopoulos describe two ways to make use of this information picked up by infrared imaging. The first compares infrared images of would-be-drunks with stock scans of sloshed and sober people. The second method drops the need for a reference, relying solely on the temperature difference detected on a person’s face.

With such a long-distance drunk detector, policemen could scan a person’s face from across the street before approaching them with nosy questions or testing their balance with absurd walking tests.

Such a system could perhaps be put to use in a car as well. If a car can check your heartbeat, it’s not inconceivable that it could be programed to lockdown if you sat at the wheel with a hot nose.