Square dance lovers move to underground garage to escape the bitter Beijing cold on Monday. [Photo/CFP]

One activity that nearly all senior Chinese like to do is square dance. From Los Angeles to Beijing to Sydney, take a walk in the evening in any neighborhood where Chinese live and there's near-certainty that you will see retirees dancing in a public square.

And they don't stop even when the temperature drops below freezing in winter. The temperature fell to minus 10 degrees Celsius on Sunday and minus 12 degrees Celsius on Monday, by far the city's coldest day this winter.

So what did the square dancers do? They moved to underground garages.