And so we are in deepest winter, which exposes a Westerner in Hong Kong to changeable behaviour.

Not by clouds or winds, but by people.

There is a wildly popular app here from the Hong Kong Observatory. It shows temperature range and carries symbols, and offers advice on accessories that may be useful to get through the day. Usually the emblems are a sun, maybe a cloud, and often rain drops. (There used to be an umbrella, but that could change, given the brolly is tantamount to a logo for the democracy protests. The Observatory defends Hong Kong people against showers, not President Xi Jinping.)

This last week there have been three days when the app has shown a jumper, a scarf and a thermometer, with no mercury whatsoever. It's the Observatory's way of imparting the frozen future: "The temperature is dipping, Hong Kong. It may descend all the way to ... 11 degrees."

Earlier this month, the Observatory went even further, reminding citizenry not just of fashion choices required to guard against the numbing impact of the predicted chill, but issuing domestic warnings. It intoned: "Do not light fires indoors as a means to keep warm."

Heating in houses is extremely rare in HK. For the few weeks of the year it actually is slightly nippy, people, evidently, must be steered away from improvisation involving embers. Living room bonfires are never a great idea but especially so in a dense city. There goes the neighbourhood. Up in flames.

Here at last we get to the changeable behaviour of Hong Kongers. This panicky attitude to cold outdoors makes no sense because, for the rest of the year, air conditioning in HK is vicious. It's December with a roof. Do Hong Kongers wince? No. I, a Glaswegian, and another couple of expats are generally the only ones lamenting the interior chill.

I had never thought of lighting a fire indoors. But now the idea has been plopped into my head, there have been some air-conditioned conference rooms that could happily have seen me turning to tinder; not for a hook up but a warm up.

Now and again, the issue of over vigorous air con is raised but change never happens. Hong Kongers get cold feet.

But I am not laughing good-naturedly at the cold weather warnings. I am working out how they can be used to expose Hong Kong to its hypothermia hypocrisy. If people here are that afraid of the cold in winter, why not acknowledge they're enduring it all year round and also paying the electricity bill? Maybe one day, Glaswegian hackers (ok, me) could get into the Observatory app, post the temperature range of air conditioned malls and cafes and only when Hong Kong has got out its mitts and scarves would it be revealed these were the conditions in the Harbour City Mall. And just about every office.

Meantime, since early December, there has been a winter range in H&M selling thermals. The store itself will be air conditioned into a fashion fridge, but no Hong Konger will notice that as they fight their way through to buy long johns. I will stock up too. But I call such thermals the air condition range.