torpor

/ˈtɔrpər/
noun
  1. A state of being inactive, sluggish, or having very little energy, often because of heat, illness, or hibernation.
    • The bear's winter torpor helped it survive the cold months without eating.
    • The hot afternoon sun sent the whole town into a lazy torpor.
    • After the heavy meal, he fell into a deep torpor on the couch.