COCOA ICE, written by Diana Appelbaum, illustrated by Holly Meade, Orchard Books, New York, 52 pages, hardcover, $16.95.

Has your family gone through a lot of ice in a search for relief from the late-summer heat and humidity? Did you obtain this ice easily from an ice cube tray in your freezer? Was it ejected almost effortlessly from your refrigerator door? The dog days of July and August would have been quite different without ice to chill beverages and protect picnic and cookout food. If your family has come to take it for granted, perhaps it would be a good time for you to journey back to a time when refrigerators had not been invented and ice was a precious commodity harvested in winter, carefully stored for summer use, and shipped in fine, high-rigged schooners halfway around the world. Your time-travel vehicle could be the marvelous book “Cocoa Ice.”

“Cocoa Ice” portrays two girls who learn about each other through a sailor who travels on a schooner to Santo Domingo with ice and returns to Maine with cocoa. Perhaps the most charming feature of the book is the real amazement with which these children — raised in a time before television or radio — contemplate each other’s lives.

The Santo Domingo girl describes how cocoa is processed, from the harvest to the sun drying and roasting of the beans. She dives for conches in the tropical ocean and experiences the excitement of the ice schooner’s arrival, especially since her father purchases some ice and her mother makes her sweet, wonderful cocoa ice.

“Ice schooners come from a land where the water is so hard the people walk right on the river — right on the river,” she marvels. “… in Maine the people build cooking fire inside their houses and the trees don’t have any leaves.”

The Maine girl describes ice harvesting and explains how the snow is scraped off the river in wintertime so the ice can freeze thicker and clearer. She describes how great blocks are cut out of the river and stored in a sawdust-insulated icehouse taller than a church. When summer arrives, her Uncle Jacob sails out on the ice schooner bound for Santo Domingo. Her mother helps her make chocolate ice cream and lets her lick the dasher.

“Chocolate comes from a faraway island where birds have pink feathers, leaves grow bigger than I am tall, and it is always summer,” she says. “Children who live on the island never have to wear boots or clean ashes from the stove because winter never comes. Best of all on the island of always summer chocolate grows on trees.”

Illustrator Holly Meade anticipated that her greatest challenge would be “to create pictures where a tropical place and warm palette must go hand in hand with a bare landscape and cool palette.” She met it admirably. The Santo Domingo pictures with their warm colors and soft curves project a tropical climate and languid pace. The more crisp, angular Maine winter pictures with their austere white, blue and gray backgrounds create a chill palpable even on a steamy August afternoon.

If you have an old-fashioned hand-crank ice cream maker gathering dust in your attic or know someone who has one, get your family together to make your favorite flavor. It will take your combined muscle power. Then when that ice cream is just perfect and you can’t wait another minute, bring out a copy of “Cocoa Ice” for a doubly delightful treat.