Workers in heating companies have been working overtime laying heating pipelines and checking boilers in Xi'an and Xianyang city in order to ensure citizens get heating on time as the weather gets colder.

Preparation for the heating is tough. Workers perform their job in cement pipelines underground, where it is dark and ventilation is weak.

"My job - electric welding, needs full attention while operating. A small mistake can cause an explosion of the heating pipelines," a worker surnamed Dang said.

The total heating area in Xi'an this year is 24 million sq m, which covers 4 million sq m more area than last year.

A worker checks a heating boiler during his shift in Xianyang city, Shaanxi province, in November 2012.[Photo/CFP]

Workers check the heating pipeline in Xianyang city, Shaanxi province, in November 2012.[Photo/CFP]