Implications of the urban heat island and global climate change and nutritional status on the human thermal comfort in Mexico City

The urban heat island (UHI) is mostly due to urbanization and it is considered as a nocturnal phenomenon, but it also appears during the day in Mexico City. The UHI in concert with the high temperatures caused by global climate change (CC) may profoundly affect human thermal comfort, which can influence human productivity and morbidity in the spring/summer period. Obesity is a disease manifested by the accumulation of excess body fat with implications for the health of people, and Mexico ranks first in overweight and obesity, where 30% of the population has obesity and near 40% is overweight. The main objective of this investigation was to determine the changes in the degree of thermal comfort of Mexico City inhabitants according to their nutritional status, because of the increase in temperatures due UHI and CC. A series of microclimatological measurements to estimate the physiologically equivalent temperature (PET) were made. Concomitantly, a series of surveys of thermal perception were applied to 1300 passersby. The results show that PET has increased from 1990 to 2010 from 0.0372 °C/year to 0.0887 °C/year in the study sites, besides overestimating the degree of thermal comfort of people with normal weight but underestimating that of overweight and obese people according to the stablished categories or classes. It is concluded that it is imperative that people with overweight and obesity reduce their weight but also should be investigated that influences the unbalanced consumption of food. It is also imperative to mitigate UHI and CC through urban architectural techniques.