Pakistan, Aug. 11 -- As dark plumes billow from overhead smokestacks, brickmakers at a kiln in Pakistan's Sheikhupura district crush coal through small holes beneath their feet into the fiery chambers below.

Workers already have to endure extreme conditions at traditional brick kilns, which burn at over 1,000C and demand constant monitoring to ensure they remain hot enough.

But they are becoming almost unbearable as climate change makes summers even hotter in a country already used to temperatures well over 40C.

Abid Hussain, a 35-year-old labourer whose clothes were covered in dark soot, told AFP the work felt like being trapped between fire below and, increasingly, above.

He is one of hundreds of thousands working in an industry tha...