The heat burns off a small amount of heart muscle.

VOA: special.2010.03.02

If the temperature drops below a certain level it sends a signal, 'turn on the heat', and that signal stays on until it gets a negative signal to turn off.

如果温度降到一定程度以下时,探测器会发送一个信号,打开加热器,直到加热器再收到关闭的信号,它就会一直开着

耶鲁公开课 - 生物医学工程探索课程节选

You want to keep spinning your mandrel so that it doesn't melt off the rod and you're going to heat your bead so that it's tacky enough to roll onto the frit and pick up pieces of the glass."

VOA: special.2009.05.18