ALA Booklist (Tue Nov 01 00:00:00 CDT 2016)

Quiet Hazel and rambunctious Karl are not friends, until they're stuck on an ice floe together. Initially, the two polar bears build a wall to block out each other, but soon they begin to enjoy things together. When the ice floe drifts back to the mainland, they realize that, even with their markedly different personalities, they can remain friends and live "cozily ever after." Hazel and Karl's differences are portrayed in a way that will be familiar even to young children, making this a worthy introduction to interpersonal relationships. The humor-infused, simple line drawings make the plight of the two bears an adventurous, rather than scary, situation, and the limited palette in blue and white with touches of orange reflects the arctic ambiance. Although it is not even hinted at in the text, the effect global warming has on polar bears is described in the back matter. This works not only as a story about two unique polar bears but also as a conversation starter about coping with individual differences.

Horn Book (Sun Apr 01 00:00:00 CDT 2018)

Karl "talks too much" (according to Hazel) and Hazel "is mean" and doesn't talk enough (according to Karl). When the unlikely polar bear duo ends up adrift on a melting ice floe together, they have no choice but to get closer and eventually become friends. Bright, full-bleed illustrations enliven the spare, predictable text. Information about preserving the Arctic is appended. Websites.

Kirkus Reviews

What happens when the loudest (and smelliest) polar bear finds himself stuck on an ice floe with the quietest and most fastidious polar bear? They build a wall! Neither Karl nor Hazel wants to have anything to do with the other, but as the ice steadily melts, they get closer and closer both literally and figuratively. Soon they're playing games, singing songs, and fishing together. As their frozen chunk of real estate shrinks to a standing-room-only platform, they sight land and gleefully jump ashore. Taking off in separate directions, Karl inexplicably searches for fish. (Hasn't he just left behind a fish-filled ocean?) Hazel, on the other hand, wants to explore and sit by herself. It doesn't take long before the suddenly lonely bears call out to each other from across the vast new wilderness and reunite, even becoming roommates. The resolution, however pleasing, feels rushed, as the bears jump straight from realizing they're friends to sharing living quarters. Olien's palette of blues and stark white offset by bold, black outlines convincingly conjures the chilly Arctic landscape. Round, horn-rimmed glasses and a cheesy smile bring Karl's gregarious personality to life, and Hazel's reticent demeanor is nicely paired with an orange polka-dot scarf. Classroom-friendly facts and links about polar bears, climate change, and the Arctic are appended. The simple storyline and art complement each other as readers are gently guided to comprehend the folly of judging a book by its cover. (Picture book. 4-8)

Publishers Weekly (Fri Oct 06 00:00:00 CDT 2023)

-Karl and Hazel are not friends,- writes Olien (The Blobfish Book) of her polar-opposite polar bear protagonists: Karl is gregarious (and maybe smells -a little- like old fish), while Hazel-s bookish shyness comes off as aloof and judgmental. When part of the ice cap that they occupy breaks off, floats away, and begins to shrink (an afterword explains the effect of global warming on polar habitats), Karl and Hazel realize that they are stuck together in an -endless sea.- Overcoming their initial mutual chilliness, they become best buddies by the time they find land. Olien-s cartooning is boldly graphic and deceptively simple: she works in crisp black outlines, clean shapes, and mostly flat shades of white, blue, and purple, with bright orange for punctuation. Yet the visual earnestness of her cartooning lends real emotional depth to her straightforward storytelling. Karl and Hazel don-t do anything dramatic on the ice floe-they make a snowman, sing songs, play -I spy--but readers will understand that the friendship they build is one that can weather anything. Ages 4-8. Agent: Brianne Johnson, Writers House. (Jan.)