Last summer, I wrote to you warning of the growing threat that extreme heat poses to both patients and the NHS, that the demand for healthcare would rise as temperatures climbed, that our hospitals were ill-equipped to cope and that investment in resilience was urgently needed (Letters, 21 July 2025).

A year on, the UK is set for another record-breaking heatwave, yet little has changed. The UK Health Security Agency has also taken the rare step of issuing a red heat alert in parts of England – signalling a serious threat to lives (Report, 22 June). This marks only the second time that a red alert has been issued. The last, in 2022, coincided with five waves of extreme heat that combined to cause an estimated 2,985 excess deaths in England alone.

NHS England data shows that between 2016-17 and 2023-24, there was a 53% surge in overheating incidents, showing clear evidence of a significant spike in demand for healthcare, especially among the very young and elderly people, and those with chronic conditions. For staff, it means stifling conditions that can exacerbate burnout, drive fatigue and increase the risk of errors as pressure on services peaks.

This is a patient-safety crisis and a matter of national urgency. Investing in building upgrades, workforce preparedness and proper resilience planning is no longer optional. It is essential if the NHS is to continue functioning.

The climate crisis is a health crisis. We have had warnings. We are seeing the consequences. The government must now act.
Dr Mark Harber
Special adviser on healthcare sustainability and climate change, Royal College of Physicians

I appreciate that the current heatwave requires serious consideration, especially for more vulnerable people, but I cannot condone the closing of schools in response (Searing UK heat leaves schools, hospitals and transport networks struggling to cope, 23 June).

By all means suspend normal activities, lessons, uniforms etc, and even allow parents who wish to – and are able to – take their children home on such days to do so. But simply sending children home is not a sensible or reasonable approach. How many of those children will be sent to homes that are cramped and overheated, and where there is no outdoor space available?

As a retired teacher, I sympathise with the view that schools and teachers should not have to deal with society’s failings. But surely this could be a national emergency, or whatever is necessary, to provide support to schools to ensure that all children are being properly cared for and protected during this climate emergency.
Sarah James
Monmouth

Reading your editorial on Europe’s heatwave (The Guardian view on extreme heat: as risks escalate, adaptation plans are dangerously lagging, 23 June), I was reminded of a UN Preparatory Commission meeting that I attended as an NGO representative in New York more than 30 years ago. Walking the streets of Manhattan after listening to climate scientists telling us that we had 20 years to solve the biggest environmental problem of the past 10,000 years was a surreal experience. City life went on as if it would go on for ever.

Months later, at the Earth summit in Rio de Janeiro, I heard Davi Yanomami warn an international Indigenous gathering about the coming ecological catastrophe. And here we are, all these years later, still denying and temporising, waiting for the world to die, not with a bang but with a whimper. What will it take to make human beings face reality and do something about it?
Linda Rabben
Baltimore, Maryland, US

As the UK faces yet another severe heatwave, London continues to reveal how poorly prepared it remains. Rail services slow down or are disrupted, transport networks struggle and many workplaces still expect employees to travel and work as if nothing unusual is happening.

The success of air-quality policies demonstrates that governments can act decisively when they choose to do so (Deaths linked to London air pollution have fallen 40%, study estimates, 24 June). The same determination is now needed to adapt our cities to a changing climate. Cleaner air is a major victory, but it should not distract us from the reality that London remains vulnerable to heatwaves that are becoming more frequent, longer and more intense.

If we can transform air quality in less than a decade, surely we can also invest in more resilient transport infrastructure, better urban cooling, more green spaces and stronger protections for workers during periods of extreme heat.

The lesson from London’s clean-air success is simple: political will matters. The question is whether our leaders will show the same urgency when it comes to preparing the capital for the climate challenges already arriving at our doorstep.
Fernando Quintana Marrero
London