Using cool materials to construct roads and walkways is an effective way of lowering urban temperatures to make cities more comfortable in hot weather, according to a new study. The research found surface temperatures were reduced by 12°C and ambient temperatures were reduced by 1.9°C after cool pavements were installed in a city park in Greece. Cities are known to exhibit the urban heat island effect, in which urban temperatures are higher than those of the surrounding rural areas. The phenomenon is created through a combination of heat released from human activities, such as air conditioning and traffic, in addition to decreased air flow and increased heat absorption by buildings, roads and other structures. In the future, climate change is likely to exacerbate the heat island effect with more frequent and extreme heat waves