What word or phrase does your mother always say?
c.1600, from Latin torpor "numbness," from torpere "be numb," from PIE root *ster- "stiff" (cf. Old Church Slavonic trupeti, Lithuanian tirpstu "to become rigid;" Greek stereos "solid;" Old English steorfan "to die;" see sterile).
torpor tor·por (tôr'pər)
A state of mental or physical inactivity or insensibility.