By Chris Hogg
BBC correspondent in Hong Kong
Environmentalists warn that densely built cities like Hong Kong could become breeding grounds for bacteria and viruses as temperatures rise.
Visibility in the territory is restricted
Research from the city says global warming and rapid urbanisation will raise the temperature in the territory by 3.5 degrees over the next 100 years.
Scientists from Hong Kong Observatory suggest the annual number of hot days will double by the end of the century.
They say the forest of buildings in Hong Kong magnifies the heat effect.
Last week Hong Kong sweltered under a thick cloud of smog, caused by stagnant conditions and high temperatures.
Now comes a suggestion that global warming is set to make things far worse and the temperature will increase almost three times faster than it did over the past century.
In the future, if the humidity and heat get worse, it will create favourable conditions for diseases to grow and spread.
Earlier this year, there was a warning that rising sea levels in the territory could cause flooding in years to come during typhoon surges, when the wind whips up huge waves.
Mainland China, Hong Kong's main food supplier, is expected to experience an even faster increase in temperature.
Environmentalists claim that harvest will suffer as a result, with the yields dropping by one tenth for each one-degree rise in temperature.
People should conserve power, they say.
The more they use their air conditioners, for example, the power they use will cause more carbon dioxide to be released into the atmosphere, adding to the "greenhouse effect" and heating up the city as a result.