With virtually no clouds or rain in summer, the rising sea temperatures lead to more atmospheric humidity.Jos Lelieveld, an atmospheric chemist at the Max Planck Institute in Germany, said: ‘These areas are warming faster than the rest of the globe, and in certain cities on top of that you have an urban heat island effect and urban pollution.’In a bid to help everyone to stay cool, city planners have built walkways and streets pointing north to take advantage of breezes that come from that direction.