With a cold winter monsoon blowing Hong Kong's way, this season has been a tad chillier than usual.
The elderly and people suffering from chronic illnesses should pay more attention to their health during this period and take extra precautions to stay warm, according to the Health Department.
Elders tend to have less fatty tissue directly under the skin, and therefore have a reduced ability to keep warm and regulate their body temperature.
A Belgian study by the European Society of Cardiology released in September found that cold weather produces more heart attacks. The study of nearly 16,000 patients of an average age of 63 years old, between 2006 and 2009, found that cases of acute myocardial infarction increased by 7 per cent for each 10 degree Celsius decrease in minimum temperature.
Researchers say this could be because during chilly weather cold receptors in the skin are stimulated, rousing the sympathetic nervous system. This leads to a rise in levels of catecholamines, which are hormones that increase heart rate, blood pressure and breathing rate, among other things.