Scientists have proposed an unusual method for combating extreme heat: applying yoghurt to the outside of windows. Research from Dr. Ben Roberts, a senior lecturer in healthy buildings at Loughborough University, indicates this technique could lower indoor temperatures by as much as 3.5°C (6.3°F).
The concept, developed as part of the Heatwave Toolkit initiative, aims to provide low-cost, effective solutions for cooling homes during heatwaves. The yoghurt forms a thin film on the windowpane, reflecting solar radiation and preventing heat from penetrating the building. Dr. Roberts explained that the primary challenge during hot weather is preventing homes from overheating during the day, leading to the exploration of shading strategies.
In an experiment comparing two identical test houses, the one with yoghurt applied to its windows showed an average temperature reduction of 0.6°C. During particularly sunny and hot conditions, the cooling effect reached the claimed 3.5°C. Dr. Roberts also noted that the yoghurt dries quickly, within approximately 30 seconds, and does not produce any unpleasant odor.
Despite the claimed benefits, the suggestion has met with public skepticism. Social media reactions to a video demonstrating the method included concerns about smell and attracting insects.
For those seeking more conventional or potentially more effective methods, Dr. Roberts' experiments also tested aluminum foil. Applying tinfoil to windows was found to be even more effective, leading to an indoor temperature drop of up to 6°C (10.8°F).
This research emerges as record-breaking temperatures become more frequent. Scientists at Reading University have recorded 15 days exceeding 30°C (86°F) so far this year. This surpasses the previous record of 14 such days set in 1976. The first day over 30°C this year was recorded on May 24, with an additional 14 days breaching this threshold over the subsequent seven weeks.
Professor Andrew Charlton-Perez from the University of Reading commented that while 1976 was historically the benchmark for hot summers, the current climate trend suggests such heatwaves are becoming more common. He stated that summers that were once rare, generation-defining events are now occurring with much greater frequency, posing significant public health risks that cannot be ignored.