An undated photo shows a member of Zhao's team fixing faults on high-voltage cables in the air in Dalian, Northeast China's Liaoning province. [Photo provided to chinadaily.com.cn]

The work gets harder in the summer and winter, scorching heat makes workers sweat in the airtight clothing, while freezing cold stiffens their hands thus making the work more difficulty which in turn means they have to stay there for longer hours.

Though tough as the task is, one mistake can cost a life. Zhao said that he is unable to sleep before the day of task. "All the details keep running through my mind like a roll of film, and I have to take all scenarios into consideration and constantly make improvements."

On the day of the work, Zhao checks every tools and equipment repetitively, such as whether ropes and sticks are wet or damp which is forbidden, and has to make sure that they are functioning well. "Safety is most important. I used to worry about my own safety before, and now worry about every one of my team member."

Whenever there's a break in work, Zhao starts thinking about easier and faster ways of doing work to better protect the team's safety.

To reach high cables, apart from climbing up transmission tower, the other way is to hang a rope ladder on the cable and climb it. It usually requires workers on the tower to help hang the ladder. But Zhao's team found a new method to hang the ladder on the 500kv extra-high-voltage cable with all workers staying on the ground.

An undated photo shows Zhao climbing up a rope ladder during a task in Dalian, Northeast China's Liaoning province. [Photo provided to chinadaily.com.cn]