While you are asleep, the bodily functions slow down and body temperature falls.
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寝る， 寐る， ねる
1. to sleep (lying down)
2. to go to bed, to lie in bed
3. to lie down
4. to sleep (with someone, i.e. have intercourse)
5. to lie flat (e.g. of hair)
6. to lie idle (of funds, stock, etc.)
7. to ferment (of soy sauce, miso, etc.)
1. to come down, to go down, to fall, to drop, to sink, to get lower
2. to hang, to dangle
3. to move back, to step back, to withdraw, to retire
4. to deteriorate, to fall off, to be downgraded
5. to get closer to the present day
6. below, south of