A prehistoric boy leaves his cave in search of warmth and discovers there’s no cave like his own. When Boy awakes in the cold morning of his home cave, his parents invite him to share their blankets. Boy doesn’t want to share and heads into the Stone Age landscape to find his own warm place. His search leads to a tree branch in a warm forest, but the resident saber-toothed tiger refuses to share. Boy moves on to warm grass, but the local woolly mammoth chases him away. Next, Boy finds warm red rocks, but the inhabiting dinosaur ejects him. Then Boy locates a warm mountain that turns into a hot volcano that sends him racing home, happy to share his parent’s blankets. Simple text and marvelous illustrations reminiscent of prehistoric cave paintings showcase Boy’s diminutive, solitary figure against a vast, empty world. Perfect for young adventurers about to enter their own brave new worlds. (Picture book. 5-7)