Effects of Temperature on Mortality in Tropical Tanzania
Mrema, S., Shamte, A., Selemani, M. and Masanja, H. 2012. The influence of weather on mortality in rural Tanzania: a time-series analysis 1999-2010. Global Health Action 5: 33-43.
Working with mortality data obtained from the Rufiji (Tanzania) Health and Demographic Surveillance System (RHDSS) for the period 1999 to 2010, Mrema et al. employed time-series Poisson regression models to estimate the association between monthly temperature - which ranges from 27.9 to 34.4°C in this tropical region - and mortality adjusted for long-term trends in three different age groups (0-4, 5-59, 60+). In the words of the four Tanzanian researchers, results indicated that "mortality in all age groups peaked up at the mid of the year," which is "the time when the temperature is relatively lower compared to other periods of the year in Rufiji." In fact, they say that if the monthly average temperature drops to a value of 24°C from the threshold, "mortality will increase by 80.7%, 65.7% and 74% in age groups 0-4, 5-59 and over 60, respectively."
In discussing their findings, Mrema et al. note that "Rufiji's population is accustomed to a tropical climate and, like any other population, is exposed to cold temperatures relative to its average climate [italics added]." And so it is that in warm and cold climates alike, it is relative cold that kills far more people than relative heat.