Introduction

The refrigerator is something of a Boo Radley, the cloistered figure in Harper Lee's To Kill a Mockingbird: it's normally pale, frequently indoors, seldom thought about much but always there, and in the end (spoiler alert) we need it to make everything all right.

The point is that among the cast of characters that tell the story of refrigeration and its impact on humanity, the refrigerator itself does not have much of a starring role. It just hangs around in the background most of the time, being cool.

You'd be forgiven for thinking that refrigerators, fridges, are nothing to get excited about. They are nothing special. There are hundreds of millions of them. Every household in the developed world has one; a quarter of American homes have at least two. And elsewhere a refrigerator is at the top of the wish list of household appliances – just below the television. When we fancy something cold – an ice cream, glass of milk, chilled beer – there they are in the refrigerator. In this day and age, access to cold is so easy there's no need to think about it.

Nicolas Monardes, a Spaniard writing in 1574, reports more of a difficulty. Cold was available to him for the right price as ice, but Monardes advises that care should be taken to avoid sources mingled with 'smelles and evil smokes … especially that which passeth by places where are rotten plantes, and naughtie tree, and where dead babies are.' All good advice then and good advice now, but thankfully refrigeration has moved on.

The fridge occupies a central place in the lives of the privileged many. To the initiated, life without one would be intolerable. By following just a few simple rules (helpfully spelled out on packets) we can enjoy foods and drinks of pristine freshness whenever we desire them. And when we run out, we simply make a trip to the larger refrigerators at the supermarket to restock.

So ubiquitous is this routine that we don't give it a second thought. We do not consider that our kitchen fridge is the very tip of a chilled tendril, one of millions more that make up a network known in food-industry circles as the cold chain. The cold chain, with its myriad nodes and branches, entangles the globe, creating a temperature-controlled transport corridor that connects the farmer's field and the trawler's hold to every grocery store chiller.

Linking to the chain gets us sashimi in Vegas, strawberries at Christmas and sorbets whatever the weather. The chain gives us choice and the luxury of time to make it. No longer is fresh produce rushed into cities during the cool of the night to be consumed within hours of its arrival. Forget the skyscrapers, subways and information superhighways – it's the fridge that makes a modern city. The refrigerators of Greater Tokyo, the world's largest urban area, provide the ingredients for at least 113 million meals a day. Without the cold chain, life in such a metropolis would be an unimaginable ordeal.

But the modern world is full of innovations, so what's the big deal about the refrigerator? The kitchen alone is equipped with all kinds of technological necessities – the electric kettle, the fan oven, the microwave … and the fridge. There is of course one obvious defining difference: all but one of them heats, and only the fridge cools.

Heat and light have been at the command of humanity for at least 100 millennia since we learned to make and control fire. We only really won the battle over cold a century ago, and still the spoils of that victory have yet to be shared with many parts of the globe. Today, the idea that hot and cold are two sides of the same coin seems second nature, but that was far from obvious to the long line of scholars run from the inspired to the bizarre, as they employed gnomes, meteors, perpetual motion machines and tortured mice to reveal the truth.

Excerpted from Chilled by Tom Jackson. Copyright © 2015 by Tom Jackson. Excerpted by permission of Bloomsbury USA. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.