Ten shopping malls have set their temperatures at an average of 22.8 degrees Celsius - still too cold for comfort for some though closer to what chilled-out campaigners want.
In 2008, the average temperature was 22.6 degrees after a survey by Green Sense of 50 malls.
But the latest survey found only The Landmark in Central met the level of 24 to 26 degrees suggested for June to September in the Energy Saving Charter on Indoor Temperature introduced by the Environment Bureau in 2012.
Green Sense measured the temperature in 10 malls in August and found the coldest on average was Lion Rise Mall in Wong Tai Sin. That was 21.7 degrees.
But the lowest mark was 19.8 at Yoho Mall in Yuen Long.
Four of the malls have joined the charter: The Landmark, Elements in Kowloon West, Luk Yeung Galleria in Tusen Wan and Citywalk 1 in Tsuen Wan. But only The Landmark met the charter requirements.
Green Sense's first survey in 2008 found 12 malls set thermostats below 22 degrees.
The group measured the temperatures in 30 malls in July by random sampling before narrowing it down to 10 based on the results of the 2008 survey, whether malls had joined the charter, complaints about temperatures and when the malls were built.
Green Sense also polled 486 shoppers in August for their views on mall temperatures - the first such survey.
About 60 percent of respondents said the malls are comfortable while 40 percent find them cold, though they are not dissatisfied. One third said they will leave a mall if they are too cold.
Green Sense said respondent satisfaction with a mall does not correlate with a low temperature as satisfaction is more or less the same at malls at 21 degrees and 24 degrees.
Also according to the survey, people find the temperature of 24-25 degrees the most comfortable, while 42 percent say their consumption is very much affected by the temperature.
Green Sense feels there is an incentive for malls to raise temperaturess because if they are too cold sales will fall off.
"We hope for a win-win situation - that the malls can be environmentally friendly and shoppers will be comfortable and costs can be saved," project manager Gabrielle Ho Ka-po said.
"People in Hong Kong should learn to shake off their reliance on air conditioners as global warming has become more intense.
"Turning on air conditioners is not the answer to hotter summers."
Green Sense will present opinions and survey results to the Environment Bureau, urging it go further in promoting and monitoring participation in the charter program.
A spokesman of Link REIT, which manages Lion Rise Mall, said the temperatures of public areas are monitored by its personnel while shop temperatures are adjusted by merchants.
The temperature of some places could be affected by factors such as a proximity to doors, he added.
Still, mall staff will evaluate the situation taking into account the survey.
He also noted that six malls under Link REIT have signed the charter.
In fact, 140 shopping malls signed the charter during June and September last year.
Next up on temperatures: Green Sense will hold its seventh No Air Con Night on October 7.