For the report, the UN agency cross-referenced data showing where the roughly 2.4 billion children on the planet live with the geographic distribution of the eight most common climate impacts. They are coastal flooding, river flooding, drought, tropical storms, heat waves -- at least three days above a high temperature threshold, which varies by country -- extreme heat, wildfires and sandstorms.The report primarily focuses on the 1.1 billion children who are exposed to at least three risks, with the most common combination being drought, extreme heat (above 35 degrees Celsius) and heat waves.That combination affects some 296 million children, including 74 million in Nigeria, 34 million in Pakistan and 32 million in India.The number of children in this three-or-more category has increased sharply over the past 20 years.Almost all children -- some 2.3 billion -- are exposed to at least one risk. Two billion are exposed to at least two, while 364 million face at least four.Of the 123,000 children exposed to seven or more climate hazards, some 46,000 are in Myanmar."Children are at the forefront of the impact of climate change," said UNICEF chief Catherine Russell.As for the worst place for a child, "there isn't a super short answer," one of the report authors, Tom Slaymaker, told AFP.'Hot spots'