The Creatures That Time Forgot

FROM PLANET STORIES:
Mad! impossible world! Sun-blasted by day, cold-wracked by night—and life condensed by radiation into eight days! Sim eyed the Ship—if he only dared reach it and escape! ... but it was more than half an hour distant—perhaps the limit of life itself! From the author of Fahrenheit 451, The Martian Chronicles and The Illustrated Man.

Originally published in the Fall 1946 issue of Planet Stories. It was later reprinted under the title Frost and Fire.