(Credit: Shutterstock) Cities around the world are getting hotter as the planet warms, and the consequences can be deadly. Researchers have linked heat waves like the one that hit Russia in 2010 — killing 55,000 people — to climate change. And even without global warming, cities tend to bake when the weather gets warm. Surfaces such as asphalt roads and concrete buildings absorb and then radiate a lot of solar energy, which can leave urban areas 6 to 8 degrees Celsius warmer than rural regions. Although some people can just crank up the air-conditioning amid increasingly brutal heat, many cannot.