Inever saw my mother in a swimsuit, and I only once remember my father in one. In Fife in the 1920s, when both of them were young, sun-worshipping had yet to catch on. When my father swam, he swam in rivers, and then warmed himself up with a brisk towelling. My mother, who never learned to swim, would enjoy a day on the sands with tea brewed over a fire and sometimes a dance or two, if anyone had a squeezebox and the rain held off. My parents remembered these things fondly during my childhood, when we might spend a summer afternoon on the local beach – it was only a 15-minute walk away – sometimes with relatives: cousins, a grandfather, uncles and aunts. Meteorology was less reliable then, and there seemed to be little question of adults “dressing for the weather” other than carrying a tightly folded plastic mac, which removed the precautionary need for a proper raincoat neatly arranged over the forearm. Otherwise, they kept most of their clothes on, even in my grandfather’s case the peaked cap, the bannet, that he wore every month of the year. When, near naked, we ran up the beach from the sea to join a fully dressed party of knitters and pipe-smokers, we completed a seaside version of Manet’s Déjeuner sur l’Herbe. Our mothers would then insist we ate what they called a “shivery bite”, a sandwich of corned beef or meat paste or cheese. On a good day, the temperature might peak at 20C (68F), though on the more frequent less-good days it might struggle to reach 13C (55F). It was the wind, bringing grey skies and rollers from the North Sea, that tended to spoil things in Fife and elsewhere on the east coast of Scotland; on the west coast the spoilers were the clouds that swept in from the Atlantic to unleash downpours on the resorts in the Firth of Clyde. Stoicism was needed wherever you were. The actor and comedian Stanley Baxter remembers the annual question from his mother to her neighbour, after the neighbour’s annual Rothesay holiday: “How was the weather?” And the neighbour’s annual answer: “Well, it never kept us in.” In these cool and sometimes damp surroundings, it was hard to imagine hot air as anything other than pleasurable. Most children’s fiction reinforced this idea, with pictures of cake and ginger beer bottles spread out on picnic cloth, and in the distance a lighthouse, a cliff, a ship and a calm sea. Nobody in these scenes seemed to perspire and yet, thanks to the presence of short sleeves and sandals, an impression of warmth was created, somewhere in the south. Might the sun ever be dangerous? At the local cinema we watched a rerelease of Alexander and Zoltan Korda’s The Four Feathers, in which Ralph Richardson loses his helmet in the desert (he is on his way to fight the Mahdist revolt) and in its absence suffers sunstroke and goes blind. But that (and later films in which crickets chirped and people sweated) did nothing to prevent a feeling that the ideal climate was more dependably sunny than the one we lived in. Aged 25, I saw the Mediterranean for the first time. I lay on the sand and got badly burnt; and then, like many millions of other northern Europeans before and since, I decided the weather and all that came with it – food, wine, manners, architecture – came close to perfection. Really, ignoring the politics and applying the sun cream, what was not to like? The great lake around which European civilisation grew: books had been written about it. This idealisation had consequences when global warming began to edge into our consciousness. Initially, one popular reaction was to predict the northward march of English vineyards under the influence of benevolent sunshine. The idea that heat could be oppressive and damaging – ruinous to many forms of life, in fact – took longer to sink in. As something to be frightened of, it seemed to belong to another age: in the imperial era of The Four Feathers, heat was often what the British dreaded most in the territories they conquered or annexed, and for many years they coped with it rather badly. In 18th-century Bengal, for example, the combination of pre-monsoon heat and monsoon humidity was deathly, but the British stubbornly continued to eat, drink and dress as though they lived in Berkshire. Their behaviour makes a vivid historical study in gluttony, stupidity and dissipation of all kinds. They drank torrents of madeira, champagne, burgundy and claret; wolfed down soup, roast fowl, mutton pie, lamb, rice pudding, tarts and cheese at dinner (a meal consumed at two in the afternoon, the hottest time of day); pelted each other with bread rolls at supper; vomited from carriages; and fell drunkenly into ditches, soiling their topcoats and silk waistcoats, their lace sleeves and their breeches, the whole splendid apparel already wet with sweat. Naturally, many of them died. The records for 1780 show a surgeon expiring after “eating a hearty dinner of beef with the temperature being 98 deg F”, though privileged excess wasn’t always to blame. Along the Grand Trunk Road and other routes used by the British military, tiny clusters of graves known as “marching cemeteries” appeared at roughly 12-mile intervals, where the casualties of heatstroke were buried when their fellow marchers camped for the night. Bengal is hotter now – the average temperature of Kolkata has risen at least 1.2C since the mid-19th century – and in May a prolonged heatwave in north India produced a record temperature in Delhi of 49.2C. France and Spain have had their hottest May on record. This month, a weather station in Catalonia registered 43.1C, which is among the hottest days recorded there in any month ever. Forest fires have broken out in Europe; dairy herds suffer in India; farmers everywhere worry about crops. A friend in Delhi writes to tell me of the cruel effects on the urban poor. “At traffic lights you see bicyclists leaning away from cars, to try to duck the flow of recycled air – even hotter than the ambient air – that’s the byproduct of the air-conditioning keeping the driver nicely cool inside.” And still we present news of heat cheerfully, ignoring the obvious like an East India merchant tucking into his six-bottle dinner. Newspapers show crowded beaches and swimmers splashing in the Serpentine, the TV weather forecasters smile when they promise us a sunny and warm weekend. (And we, too, are glad.) Saffron O’Neill, an academic at the University of Exeter, wrote recently of a conflict in the coverage, which perhaps represents a conflict in ourselves. A study of the European media, she wrote, revealed “a mismatch between the text of the articles and the accompanying visuals”. The headlines announced news of unprecedented heat and the consequences for the sick and elderly people; the photographs featured people having “fun in the sun”. The mismatch was particularly prominent in the UK, O’Neill wrote, which perhaps said something “about how British culture narrates the experience of very hot weather in our historically mild climate”. It does, it does. I look at the forecast for Rothesay and what do I see? Cloud, some sunshine, light rain showers, a moderate breeze, a maximum of 14C. Rejoice! Ian Jack is a Guardian columnist