Evaluating Human Cooling Strategies in Urban Environments

Prolonged periods of high temperatures can have a negative impact on the health of humans causing heat stress, heat stroke and, in the most serious case death. This phenomenon was seen during the 1995 heat wave in Chicago and the 2003 heat wave in France, where many deaths were attributed to the extreme temperatures. This issue will likely become more prominent in the future due to the probable warming caused by anthropogenic climate change.

Public health units, and other similar organisations, have begun to produce information sheets on cooling strategies that the public can use during periods of hot temperatures. While these strategies are sound theoretically, few empirical studies have been done to evaluate their effectiveness. The purpose of this study was to use field measurements to evaluate the effectiveness of four different cooling strategies (using the shade of a building, using the shade of trees, using an umbrella for shade and changing the albedo of a person's clothing) in two different settings (one representative of a downtown setting and one representative of a residential setting).

Evaluation of the strategies consisted of determining how much a strategy decreased the value of the COMFA heat index. Wilcoxon Rank-Sum tests determined that all four strategies decreased the COMFA value by a significant amount (α = 0.05). The albedo and building shade strategies were more effective than the umbrella and tree shade strategies due to their greater ability in decreasing the amount of solar radiation absorbed.