As Hong Kong sweats through a heatwave after recent bouts of unexpectedly heavy rain, a new international study has put the focus on roller-coaster weather taking an increasing toll on lives. Those living in places with wildly swinging temperatures over the course of a day or week are more vulnerable to health problems such as heart attacks, respiratory ailments, and increased heart rate, blood pressure and cholesterol levels – leading to their mortality risk being significantly higher. That is according to a study by the University of Hong Kong in collaboration with 372 communities in 12 countries. With onset of warm, wet weather, Hong Kong should be on guard against spread of Zika virus It found that China – Hong Kong included – was among those countries experiencing the biggest fluctuations in temperatures that pose a greater health risk to citizens. HKU environmental epidemiologist Dr Tian Linwei, who co-authored the study, warned the government of the huge public health impact of climate change and urged officials to be proactive in policymaking. “Hong Kong is certainly under the effects of climate change as we expect to see extreme weather more often,” Tian told the Post. “The Food and Health Bureau and Environment Bureau should work together to develop relevant policies on preventing the damage of climate change, as well as to plan ahead for the medical demands.” The study, published in the peer-reviewed journal Environmental Health Perspectives this month, is the first to look at the relationship between mortality rate and temperature variations over the span of a day and a week. Some countries have experienced a bigger impact on the health of their citizens than others, according to Professor Shilu Tong of Queensland University of Technology in Brisbane, lead author of the study. China, including Hong Kong, saw a high mortality rate of 1.45 per cent – measured during a mild season and recording temperature changes over seven days – second only to Moldova, with the highest rate of 3.1 per cent. Anger as Hong Kong Observatory refuses to issue red warning amid downpour They were followed by 1.08 per cent in Japan, 0.89 in South Korea, and 0.86 in Taiwan and Spain. The research model did not just measure temperature changes, but also considered other factors such as locations that could add to the impact on health. The same impact may be caused by a change of abut 3.2 degrees Celsius in Hong Kong, or about six degrees in the mainland city of Tianjin. That was why researchers were unable to specify how much of a temperature fluctuation could be considered significantly harmful to health. But Tian pointed out: “In theory, even a one degree change in the temperature can bring harmful effects to health.” The Observatory issued another “very hot weather” warning yesterday as temperatures hit 35 degrees, among the highest so far this year. Recently, forecasters have repeatedly warned of more extreme and inclement weather patterns as part of global climate change.