Hi, In message <BAY156-W248FECDB93ECAC113B9B1FAEA40@phx.gbl>, Alberto Castillo <ezeizabotgard@hotmail.com> writes >recover. The reason is evident: to reach 46 C at the core the outer >portion must be almost boiled. The laws of thermodynamics beg to differ. If your bulbs are exposed to a constant 46C for long enough (above there is mention of 2 hours) the temperature at the centre will be the same as outside. -- David Pilling email: david@pilling.demon.co.uk web: http://www.davidpilling.net/