Dying from Heat and Cold in Chiang Mai, Thailand

Authors Guo et al. (2012) note that knowledge of the health effects of extreme temperatures on mortality comes mainly from developed countries, particularly from regions with temperate climates; and they say that "few studies have been conducted in developing countries, particularly in tropical regions." Thus, they go on to conduct one such study for Chiang Mai, Thailand (18°47'N, 98°59'E), with a population of 1.6 million people as of 2008.

More specifically, Guo et al. used a Poisson regression model combined with a distributed lag non-linear model to examine the non-linear and delayed effects of temperature on cause-specific and age-specific mortality, employing data from 1999 to 2008, while controlling for season, humidity, ozone and particulate matter (PM₁₀) pollution.

In doing so the three researchers, as they describe it, found that "both hot and cold temperatures resulted in immediate increase in all mortality types and age groups," but they say that "the hot effects on all mortality types and age groups were short-term, while the cold effects lasted longer." And, of course, the cold effects were greater, with more people dying from them than from the effects of heat.

Once again, extreme heat is shown to be less deadly than extreme cold.