A state in southern India is running a competition for designers to produce an "air-conditioned" jacket for outdoor labourers with prize money of more than 20,000 dollars up for grabs.

Local authorities in Kerala have challenged individuals and research organisations to produce a prototype cooling jacket that could be used by workers who toil in hot weather.

"If it is successful, then it is bound to increase their efficiency as they will be in an air-conditioned environment," a senior official from the industries department, T. Balakrishnan, told AFP.

He said 10 viable ideas would be selected by an expert panel, with each inventor then given 100,000 rupees (2,200 dollars) to develop the concept.

"The winner will be awarded with one million Indian rupees (22,000 dollars) and monetary assistance will be given by the state to manufacture the prototype," he said.

Kerala, a southern agricultural state famed for laid-back tourism and its tropical beaches, is not subjected to the extreme dry heat known on the plains of northern India.

Deaths from sunstroke are reported each summer in India, when temperatures can push 50 degrees Centigrade (122 degrees Fahrenheit).

Millions of workers from Kerala also leave their homeland to work in the furnace-like temperatures of the Gulf, often in the construction industry.

"I think this cooling jacket will be a gift for our men working overseas," Balakrishnan said.

It is not the first time Communist-ruled Kerala has invited inventors to help with a problem.

Last year, officials announced a six-month competition for engineers to design a mechanical coconut plucker.

Kerala has 7.9 million hectares (20 million acres) of coconut tree plantations and produced a massive 5.6 billion coconuts in 2007-08. Some 3.5 million families are involved directly or indirectly in the industry.

But socio-economic changes linked to economic growth, as well as the risks involved in climbing trees up to 30 metres (100 feet) high, mean the industry is struggling to find people to climb the trees and pluck them.

The response to the contest was remarkable, Balakrishnan said, but none of the proposed machines has been successful.

M.M. Lawrence of the Centre of Indian Trade Unions welcomed the cool jackets idea.

"The concept is innovative and worker friendly," he said.