As Britain endures its third heatwave of the summer, the Advertising Standards Authority (ASA) has warned consumers against portable air conditioning units sold online that make exaggerated claims, such as being "designed by NASA engineers" and able to "cool a room in 90 seconds". The regulator says some companies are exploiting surging demand during the hot weather to lure desperate customers with promises the products cannot actually fulfil, meaning shoppers risk wasting money on devices that perform no better than a cheap fan.

A Daily Mail search found one advert, appearing to feature AI-generated videos, for a £69 portable unit claiming to bring a room down from 34°C to 17°C in under two minutes via a "patented airflow acceleration system". However, one buyer complained it did not cool their room at all and likened it to a basic fan. The ASA cautioned that such ads commonly appear during hot spells, making it easy to be drawn in, while YouTuber Stuart Matthews bought a similar cube-shaped device to test its cooling claims live on camera.