Cities suffer from the so-called Heat Island effect whereby the temperature inside the city is higher than it should be. The World Health Organization (WHO) warns of the influence of the heat island on human health and many cities are already beginning to change their way of designing the city to take into account the thermal comfort of public spaces.
The Heat Island phenomenon is due to the fact that the materials that predominate in cities such as asphalt and cement on streets and on roofs of houses retain heat. These materials are usually predominantly dark in color, aggravated by heat absorption. In addition, under normal conditions the earth contains water particles that evaporate with the sun’s rays and contribute to cooling the environment, something that does not happen in highly artificial urban environments. Another factor that contributes to the temperature is that cars, buses, industry and other urban activities generate heat.
The orientation of the buildings, the presence of nature, or the density of traffic are essential elements when planning an urban environment adapted to climate change and offering thermal comfort zones to its fellow citizens.
Cities such as London (National Urban Park), Paris (Adaptation Plan) and Barcelona (Plan to Promote Green Infrastructure) are advancing in the incorporation of nature to increase the reflectance of solar radiation, provide shaded spaces for the population and connect green areas establishing climate refuges for citizens. One of the starting points for developing these strategies is based on developing heat maps that allow knowing the hot spots in the city and designing strategies to solve this problem. To get an idea of the Heat Island effect we recommend the maps produced by Hotmaps.