Cold/hypothermic induced longevity (CHIL) increases maximum lifespan, but the acute effects of CHIL on senescence,
herein defined as the acceleration in mortality rate with age, have not been examined. Furthermore, dietary restriction
(DR) also increases maximum lifespan, but the effect of DR on senescence remains controversial. Here, we demonstrate
that in C. elegans, both DR and CHIL significantly reduce senescence. Furthermore, even at midlife, transfer to
or from a life-extending condition acutely changes the rate of senescence. These results are consistent with the hypothesis
that previous temperature or dietary conditions cause irreversible damage to the organism, but future acceleration of this
damage is solely dependent on the current temperature or dietary regimen.