“As temperatures soared over 40 degrees in July 2022, we collectively witnessed the immense challenges faced by cities, communities and critical infrastructure” — Shade the UK.

IT IS the hoary chestnut of those who deny the dangers of global heating that cold weather is responsible for far more deaths than heat. Currently, this is indeed true. Cold increases the risk of heart attacks, strokes, and respiratory illnesses — but time does not stand still.

Hot regions are getting hotter while previously cold regions are catching up. This phenomenon is called Arctic Amplification. In some warmer countries, heat-related deaths are already matching or surpassing those from cold, and that trend can only continue on our present course.

Heat causes deaths through dehydration, heatstroke, worsening of chronic diseases, and the increased spread of vector-borne diseases like dengue fever or malaria as the climate warms.

In addition, secondary causes of death will increasingly include famine from drought-induced crop failure.

But tropical and equatorial regions are already surpassing human and ecological heat tolerance limits for another reason.

When we talk about temperature, we’re typically referring to dry bulb temperature — the standard thermometer measurement. However, this reading doesn’t account for a climate change-induced increase in atmospheric humidity, which plays a major role in how heat affects the human body.

Wet bulb temperature measurement, on the other hand, does take humidity into account to show how effectively our bodies can cool themselves through sweating. When humidity is high enough that sweat can no longer evaporate, even temperatures as low as 29°C can become lethal, even with a short exposure time.

It is depressing and deplorable that this most frightening of scenarios is played down or derided in sections of the media that continue to spread disinformation on behalf of powerful sponsors.

Unions take action

And it is no longer just the global South that faces dire consequences. The number of extreme heat days has doubled in nearly all countries.

It is not surprising, then, that workforces, even in this country, are worried. Although employers have a duty to ensure a reasonable working temperature, at present, there’s no legally mandated maximum temperature for workplaces in Britain. Public health strategies must adapt to both current risks and future projections.

Unions like Unison and Usdaw are calling for a legal maximum working temperature of 30°C (27°C for strenuous work) to protect workers’ health and safety, with employers required to take action when temperatures rise above 24°C, according to the TUC and Unison. Many unions are also pushing for increased measures to protect outdoor workers from heat, including shade, water, and regulated work schedules. 

Shade the UK, whose mission is to adapt the built environment and public spaces to protect the vulnerable against a changing climate, explains their motivation:

The record-breaking summer of 2022 confronted us with a dreadful prospect: one for which we need to be prepared.

During a recent community assembly organised by Shade the UK on the subject of preparation and adaptation, there was a strong emphasis on the importance of community support groups, which proved so effective during the Covid-19 pandemic. These groups could establish community “cool hubs,” along the lines of the warm hubs established during the fuel crisis, potentially located in cellars and church vaults. As for an insect invasion, screen doors and windows were seen as essential.

Other proposed strategies included traffic reduction; painting roofs white to reflect the heat of the sun while keeping windows closed and shuttered during the day; reconfiguring the working day to include a Spanish-style midday siesta when the sun is at its hottest, and confining working hours to early morning and late evening. Reviving public drinking fountains was considered a priority, and misting systems, inspired by the Egyptians and Persians, who used porous clay jars and water-soaked cloths to cool air as it evaporated, were suggested.

Also advocated, of course, was the need for planting more trees which provide shade and have a cooling effect, establishing more green spaces and rewilding previously manicured parkland.

Local action is all very well, but the government itself doesn’t have a plan to protect lives. It’s time they got the message.

In its latest outlook, the Met Office forecasts that this summer is twice as likely to be hotter than normal.

When temperatures become unbearable, people all over Britain will join the “heat strike” and stay at home to stay safe. Climate groups and union branches will set up local events from lunchtime walkouts to “cool stations,” and other activities. Sign up to find out what you can do on the hottest day and get the heat strike flat pack — www.heatstrike.uk.