Loss or absence of emotional care. Allows function without an emotional drive or interferance. May be triggered by a situation, internal or external, or may just 'slip on one' for no obvious discernable reason. Occassionally I wake up in that state and stay there for a few days, for instance. Numbing may also occur during continuou stress, sudden stress or immediate crisis.
This type of numbness is often beneficial in possibly stressful situations, as my brother, Jjr, attempted the same idea (carrying pan outside, only he tried the long way instead of the short one I went for), didn't recognize the heat until it was too late, panicked and dropped it, thus getting a really nasty burn. If his emotions didn't 'get in the way' he would've likely taken stock of the situation, realized it wasn't working and tried another route. He also probably wouldn't've tried the long way 'round, he's generally smarter than that.