The great Ben Nevis glow-up: how I hiked up a mountain and became an artwork

The UK’s most stunning locations have been turned into works of art by 11,000 ‘lumenators’. Our writer grabs a geolight and gets a wind-chilled, freezing cold thrill on Britain’s tallest peak

Microplastics found in human breast milk for the first time

Exclusive: Researchers concerned over potential health impacts of chemical contaminants on babies

Toxic air pollution particles found in lungs and brains of unborn babies

Particles breathed by mothers pass to their vulnerable foetuses, with potentially lifelong consequences

Landlines by Raynor Winn review – back on the trail

The author of The Salt Path returns with another heartwarming odyssey, this time on one of the wildest walks in Britain

Increase in LED lighting ‘risks harming human and animal health’

Transition to blue light radiation across Europe increases suppression of sleep hormone melatonin, say scientists

I sat on a wet towel, my stepfather sent apocalyptic texts, but our long-term response to the UK’s heatwave must be action

As our brains return, briefly, to room temperature, it’s time to think about what we do next, writes Emma Beddington

‘I call it sauna head – your ego disappears’: how the UK got hooked on heat

From a hut by a Welsh river to a converted horsebox on the beach, saunas are appearing in unlikely spots all over the country

Beat the heat: how to stay cool in hot weather

UK authorities have issued a health alert after temperatures were forecast to top 30C on Friday. Here are some tips on how to stay well

Do wood burners add to air pollution in cities? Yes, say citizen scientists

Pioneering Bristol study blames the solid-fuel burners in people’s homes for breaches of World Health Organisation guidelines

Global heating is cutting sleep across the world, study finds

Data shows people finding it harder to sleep, especially women and older people, with serious health impacts