A fascinating and thorough look at how both animals and humans regulate their body temperatures.
Beginning with the difference between warmblooded and coldblooded species (the terms endothermic and ectothermic are introduced but not used), Arnold devotes spreads to such topics as muscle movements, sweating, the shrinking and expanding of blood vessels in the skin, fat, body coverings, and the size and shape of an animal. Behavior can also affect body temperature: animals or humans can seek/avoid the sun or a breeze, cool off or warm up with water, find shelter, or hibernate/estivate/migrate. The one misstep is a minor quibble—a sentence incorrectly states that “No animal can live if its body temperature falls below freezing.” The copyright page lists the illustrations as having been done in watercolor and Photoshop, but readers would be hard-pressed to see any evidence of digital artwork here. The spreads and spot illustrations have that blurry, batik quality of watercolors that lends itself so well to nature scenes, while the insets are well-delineated, allowing readers to understand the structures discussed in the text. Every animal is labeled, making this a great jumping-off point for further research into readers’ favorites. A glossary and author’s note round out the text.
A stellar addition to a rather empty shelf. (Nonfiction. 6-10)