Why does the human use a large amount of energy when exposed to cold temperature for a long period of time

So they won't be exposed to hypothermia.

Explanation:

Hypothermia is when your body's temperature drops. Your body's energy is a way of keeping warm

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what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.