Buckle in, Britain: it might have been late getting started, but it looks like we’re set for another sweltering summer, with record-breaking highs of 37C forecast for Thursday. By this point, you know the drill: swap the duvet for a sheet (and a shared bed for a single), wear shorts if your employer allows, carry water with you on the train, and get off at the next stop if you’re feeling unwell. The temperature will drop eventually; in the meantime, the spirit is broadly one of keep calm and carry on.

We’ve been here before. Last year was marked not just by England’s rocket-fuelled run through the football World Cup, but the concurrent six-week spell from late June to mid-August, when daytime temperatures in parts of Britain consistently topped 30C (86F). Even climate deniers were perturbed. That summer was the joint hottest on record. But then the mercury dropped, bringing with it relief – from the discomfort of the sweltering heat, yes, but also having to confront the visceral threat of climate crisis.

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In Britain we are lucky. Our temperate climate has given us the option of ignorance for so long. In Australia, Asia and the Middle East, the apocalyptic vision that the Guardian’s global environment editor Jonathan Watts and I described in our piece on “the city at 50C” is already a reality. Britain is not immune. Exactly one year ago the Met Office issued a heatwave warning on the hottest day of 2018 – but for many, the arrival of autumn quite literally took the heat out of the issue.

We can’t afford to let that happen again – to let it keep happening. We cannot slide into record-breaking summer after record-breaking summer, sedating ourselves with Mr Whippy ice-cream, until the crisis reaches a point where it will occur to no one to suggest a lower-tog duvet as the solution. When we talk of these ever-increasing temperatures, we tend to talk of treating the symptoms, not the cause: wear breathable fibres, freeze your water bottle, head to a beer garden.

The trouble is – unless you are elderly or otherwise already vulnerable – it is just so easy, even enjoyable, to weather the hot temperatures. You raise your hemlines, you buy a fan, then the temperature drops and the fan goes away until next year. The problem of heat is, to a large extent, swept from view with the change of the seasons (or what passes for them these days). But – out of sight, maybe out of mind, but very much still the backdrop – the problem continues to grow.

Even under the most optimistic predictions for emissions reductions – which it is almost unimaginable that we will be able to achieve – we face many more decades of intense heat. Experts say that almost half the world’s population will be exposed to potentially deadly temperatures for 20 days a year by 2100. We reckon with the flicker of this possibility every summer – nearly 700 more deaths than average were recorded in the 15-day peak of last year’s heatwave in England and Wales – yet we are still slow to act to mitigate those of the future.

Facebook Twitter Pinterest ‘We cannot keep sedating ourselves with Mr Whippy ice cream until the crisis gets worse.’ Photograph: David Levene/The Guardian

We continue to build housing designed to keep heat in, creating “death traps in hot weather”, and leave cooling measures to those who can afford them. We privatise precious green spaces that help to reduce the impact of heat and we build with asphalt, brick, concrete and glass, which exacerbate it. We have learned to change our behaviour in response to rising temperatures – lingering in the frozen goods aisle of the supermarket, organising our lives around air conditioning – when what urgently needs to change is the structure of society. Not now – but yesterday.

Yes, tackling wider climate change by reducing emissions should be the pre-eminent priority. But – in the knowledge that heatwaves will be worse even under the (unlikely) best-case scenario – at the same time we need to be making practical, structural changes to ease the impact of prolonged periods of extreme temperatures on our systems and society. Introducing measures to protect against overheating in planning regulations would be an obvious step, as would protecting access to green spaces, if not increasing their number. An analysis today from the Office for National Statistics found that there was more concrete than greenery in the average urban residential garden, inevitably compounding the “heat island” effect.

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For that to happen, we need to keep heat front and centre, even when the weather is cooler; and we must recognise that it can’t be left to individuals to find ways to cope. The issue may recede with the seasons, but it is not going to go away. Look to Asia, Australia and the Middle East for a glimpse of what the future might hold – we may reflect on this period and wonder why we did not act while the sun merely shone. In the meantime, recognise this heat for the harbinger that we know it to be. Feel the sweat drip off your elbows, the heat pummel your skin. It may be uncomfortable now, but it can’t be simply endured for ever.

• Elle Hunt is a commissioning editor for Guardian G2