Ruapehu crater lake hottest in years

Scientists warn the crater lake on Mount Ruapehu is the hottest it's been in two years. Te Wai a-moe reached 42degC on Tuesday after rising by half a degree a day for the last two weeks. Only one percent of post-2009 temperatures have exceeded 42degC. Brad Scott is a Volcano Information Specialist for GNS. He talks to Guyon Espiner.