Heatsink in radiator blows up in school

On 4 April 2011, during lunchtime, the heatsink inside the radiator started blowing up, and even our own headteacher's report exaggerated that this might be the case. At 12:30, the temperature went up to 64C. The 46C difference is huge enough to blow out the smell. On our road network, there was several delays and traffic jams due to the problem. When the older students were going for dinner, they were vulnerable to it. The year 3 and 4 looked good than 5 and 6, leaving further disruptions.