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Dougal explores the secret lava tubes of Etna and climbs Stromboli for a face-to-face encounter with an erupting volcano. Meanwhile, Leo finds evidence of a volcano where you’d least expect it.

Leo and Mike enrol as pylon workers in Florida to find out how the men who do it avoid killer lightning strikes, and we meet the UK boy who cheated death when he was struck by lightning.

The team explores the phenomenon of the earthquake. Clare and Mike train with one of the top international rescue teams. Leo takes on a dangerous cliff climb with a very special partner, whilst Dougal and Zoe are in Tokyo to find out how people stay safe in the most earthquake prone city on the planet.

The team investigate the terrifying giant waves of the tsunami. Zoe and Dougal travel to Japan to meet child survivors of the 2011 disaster and test ride the brand new tsunami escape pod. Meanwhile, Leo attempts a very unusual route to safety when all else fails.

In this Fierce Earth special, Clare and Leo head to Death Valley in California which is officially the hottest place in the entire world, with record-breaking temperatures of a sizzling 57 degrees centigrade. The pair endure a special test to work out what colour clothing is the best to wear in heat; Clare finds out what it's like to go to school in the world's hottest place; Leo becomes one of the first people in the world to climb the hidden canyons. Later, in the intense heat, Leo completes a section of the Badwater Ultramarathon, a race five times longer than the London marathon.

The team investigates wildfires and discovers how they rage all over the world leaving a trail of devastation and destruction. We travel to Colorado and meet one of the youngest female fire fighters in the US who has been on the front line and tackled wildfires head on after her house and part of her neighbourhood was burnt down. Zoe experiences first-hand what it feels like to try and outrun a wildfire and Leo is challenged to see how long he can survive in raging heat of up to 800 degrees in a special fire chamber experiment.

The team encounters the most feared event in weather - the hurricane. Florida-based stormchaser Mike takes us on a wild ride into the eye of the storm and we meet three childhood friends who had their lives turned upside down when Hurricane Ike struck their homes in Texas. Leo is challenged to take hurricane-force winds head on and Zoe learns how we are designing buildings to cope with their awesome force.