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Dying from Heat and Cold in Chiang Mai, Thailand
Guo, Y., Punnasiri, K. and Tong, S. 2012. Effects of temperature on mortality in Chiang Mai city, Thailand: a time series study. Environmental Health:

The authors 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.

What was done
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.

What was learned
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.

What it means
Once again - see Health Effects (Temperature - Hot vs. Cold Weather) in our Subject Index - extreme heat was found to be less deadly than extreme cold.

Reviewed 26 December 2012