Cold facts after heat turned up on thermal wearTop News | Sophie Hui 16 Jan 2018
Price has little to do with warmth, according to a Consumer Council test which found that thermal underwear with a heftier price tag came up short in terms of heat retention.
The watchdog tested 15 models of thermal daily wear and five models of sports or outdoor clothing, priced between HK$99 and HK$559. They were found to vary with a difference of more than double in thermal-retention value.
The test revealed that a HK$99 Baleno Thermal Extra men's long-sleeved underwear - the cheapest product tested - had the best heat retention among all 15 samples.
Its thermal-retention value increased from 0.23 clothing insulation units to 0.26clo after being washed 30 times - so the more it was washed, the warmer it got.
In contrast, a HK$559 Columbia Omni-Heat Midweight Stretch Baselayer (men's) underwear had the worse thermal retention value of 0.1clo.
Among women's clothing, a Wed'ze FreshWarm women's sample (HK$119) had the highest thermal retention with 0.32clo.
"The test indicated that there is not necessarily a direct correlation between the price and the thermal-retention value of the products," said Clement Chan Kam-wing, chairman of the watchdog's publicity and community relations committee.
The thermal-retention value of some other samples increased after being washed.
However, not all thermal underwear share the same trait as a HK$159 Bbminor Warm Infinity's retention value dropped 60 percent to 0.06clo after being washed 30 times.
Besides the thermal-retention value, the test also compared their water-vapor permeability, sweat wicking, quick-drying performance and durability.
Eight daily wear samples had poor sweat-wicking and quick-drying performances as they took over a minute to completely absorb the water droplets.
But four of the five sportswear samples absorbed the water droplets in just one to two seconds.
Daily wear models were faster in moisture evaporation.
"Consumers are advised to choose according to their individual needs," said Chan. "For instance, if you are a person who is sensitive to coldness, you should consider a daily model with good thermal-retention performance.
"On the other hand, if you enjoy an active physical lifestyle, your choice should be a sportswear model that provides better performance in terms of water vapor permeability."
Meanwhile, the Hong Kong Observatory has forecast that it will be warmer tomorrow, with temperatures reaching 22 degrees Celsius.
It is unclear if the mercury will go down toward the end of the month.
The observatory's extended outlook showed there's a 20 to 30 percent chance of the temperature dropping to 10 degrees on January 27.