Heat & Health in vulnerable populations

The increasing temperatures due to climate change pose a major threat to human health with increasing morbidity and mortality as a result. The level of vulnerability of humans due to the heat depends on many factors, such as environmental parameters, physiological and anatomical characteristics and behaviour. The aims of the current thesis were to investigate the effects of sex and age on vulnerability in the heat and explore the use of thermal models to provide individualized advice regarding heat stress and heat strain prevention. It was shown that the critical Wet Bulb Globe Temperature limits differ between sexes. Therefore it needs to be considered to have sex as a separate factor in thermal models and indices, in line with the observation that heat-related mortality is higher in elderly women than men in the Netherlands. It is also shown that people are able to adapt to the increasing ambient temperatures by an upward shift in the minimum mortality temperature, e.g. the ambient temperature at which the least amount of people die. Furthermore, it was shown that caretakers cannot estimate heat strain of their children reliably. More effort is required to educate caretakers in thermal strain detection and reduction. The tool ClimApp was shown to be a valid and user-friendly tool to predict heat strain. It may be incorporated in heat policies to reach a broader audience and vulnerable populations to provide relevant, individually focused advice regarding the risks of the heat and precautionary measures.