By the colder outdoor temperatures. Its kept hot and humid here to recreate the climate of south east asia. But all that heat comes at a cost. Electricity bill is about £3 million a year, which is obviously very significant to what were trying to do now is move towards much more sustainable ways of heating this tropical environment. So moving to things like Air Source Heat pumps. For more stories from across the uk, head to the Bbc News website. Youre live with Bbc News. We are now getting live pictures from the city where we know there has been an incident. There arent too many verify details for you but it appears that a man has wended many people. Reuters are saying that p many people. Reuters are saying that up to 19 people. Other agencies are putting that number a little bit