Nothing goes together like Thanksgiving turkey, cranberry sauce, pumpkin pie and the Heimlich manoeuvre. So it is altogether fitting, as well as sensible, on the occasion of the annual American festival of gluttony, to pay attention to a city landmark that is too often overlooked: New York's vivid, state-of-the-art "Choking Victim" poster.

Since the late Seventies, all New York eateries have been required by law to prominently post the Heimlich how-to chart, which depicts Dr Henry Heimlich's handy method of expelling an unwanted ort (crosswordese for "table scrap") from the windpipe of a hapless co-diner. Heimlich's as- yet-untrademarked invention - a vigorous and brisk hug in which the rescuer places his arms around the choker from behind, clasps the hands, then jerks the doubled fists smartly upward into the victim's stomach - has saved the lives of thousands of food-wolfers.

A commonly cited example of tragedies in the pre-Heimlich era is the untimely demise of Mama Cass Elliot, the sofa-sized songstress of the Mamas and the Papas who was rumoured to have choked to death on a ham sandwich in London in 1974. It turned out that the ham sandwich on Elliot's hotel bed was a red herring - she had succumbed to a heart attack. But had she swallowed the ham wrong, no one would have known how to dislodge it.

Depending on how much attention the average Manhattanite has managed to wrest from his plate at Pho Viet Huang, Red Flame Diner, or one of the 18,000 other local nosh joints, he will have noticed to a greater or lesser extent the Heimlich charts on the wall. A while ago, New York's ace Department of Health grew concerned that, in a city like New York, where dining in is the exception, habitual restaurant-goers may suffer from over-exposure to Heimlich signs, and that, over time, the charts risk becoming so much civic-minded wallpaper. When the gravlax goes down the wrong way, the typical jaded Manhattanite diner, to his peril, is physically incapable of registering the lifesaving instructions that overhang his seat.

So, when edgy Parson's School of Design students offered to have a go at repackaging the message, the City clinked glasses in joyous anticipation. The old version of the conscientious poster was not unattractive, but its no-frills design recalled the sort of public service announcements that people tend to ignore - such as the hairdryer label pictogram that implies you ought not plug in the device mid-shower; or the thoughtful airline disaster-procedure sheet that lies untouched in the back pocket of the plane seat in front of you.

But in a matter of months, Parson students knocked the old choke chart out of the water with a punchy new suitable-for-framing model that smacks more of El Lissitsky than Rube Goldberg. With cut-out applique art of plate, fish skeleton and lemon slice in cheery periwinkle blue, geranium red and egg-yolk yellow, accented by ravishingly well-muscled rescuers and rescuees in a stirring shade of royal blue, it could pass for one of those Suprematist compositions in which a red wedge beats a white square all hollow, or a red square intimidates a black one.

Alas, far too many New Yorkers have not paid sufficient attention to the new, improved model in spite of all its jangling vigour, so after this Thanksgiving's chowdown, chances are there will be less of us to kick around - which will leave more room in the restaurants for those cautious souls who remember to chew each mouthful 32 times.