In winter, I get a million greetings from friends living in northern China who tell me how lucky I am.  

I live in Shenzhen, Guangdong Province, along the southern coastline of China. Many northerners have the misconception that it's warm all the time in the south, or that even if it isn't, it's a lot warmer than the north, so southerners shouldn't complain about the cold. 

Southerners, on the other hand, think it's unfair that northerners get central heating in the winter. This debate has been going on for years and has divided people in China.

Central heating started during China's planned economy era, and the heating line roughly follows the Qinling Mountains. Those north of the line have central heating in the winter, and those south of it don't and must rely on store-bought heaters to keep warm. 

I lived in the north for five years, so I know how harsh their winters can get. I have also traveled to the northeast corners of China to Harbin, where they say if you spit, it instantly turns to ice and hangs on your lips. 

It's an exaggeration, most of the time. But once I saw a girl drop her popsicle (yes they still eat popsicles at -20 C), and it immediately stuck to the ground. They have every bit of right to central heating. 

But there's no need to despise southerners. It might be warmer, but it's no sauna during winter time. 

Last week, a whiff of cold air arrived in Shenzhen, bringing the temperature down to 6 C. Some friends heard me complain and snickered, "How cold can it get, it's above 0 C!"

But in the south, you can't measure coldness that way; you have to add the humidity. When outside is 6 C with 80 percent humidity, the coldness seeps into the house, and no matter how much you move about, shake or shiver, the coldness sticks to you like a mask and stabs you like thousands of needles. 

How can you possibly tell me there's no need for central heating in the south? 

Have you ever been in the home of a northerner during winter? Your glasses fog up, and you take off your coat, sometimes even your sweater. It feels like stepping into spring. In the south, you crawl under your icy blankets and try to warm up the bed with your body temperature. 

There really is no need to fight. The coldness is an enemy to us all.