A recent heatwave in the UK is causing more discomfort than previous ones, as noted by scientists. The increased humidity levels during this heatwave, nearly double that of recent hot spells, are raising concerns for health risks like heatstroke and cardiovascular issues. Certain areas under a red heat health warning may experience warmer sensations than during the 2022 heatwave, even if temperatures are not as high.
The combination of high temperatures and humidity, known as the ‘wet bulb’ effect, can hinder the body’s natural cooling process by preventing sweat evaporation. The current forecast, with temperatures around 30°C and humidity nearing 50%, presents a higher wet bulb reading compared to the 2022 heatwave. This elevated humidity requires more effort from the body to cope, despite slightly lower air temperatures.
The Met Office highlights the specific dangers of high humidity, including heat stress, dehydration, and in severe cases, heatstroke or cardiovascular complications, especially for vulnerable groups like the elderly and those with existing health conditions. Forecasts suggest that temperatures may feel as high as 50°C, even if not reaching that level.
Meteorologist Jim Dale of British Weather Services warns of worsening conditions due to a prevailing heat dome and the influx of hot air from neighboring regions. The humidity plays a crucial role, amplifying the heat index and making temperatures feel considerably hotter than they are. Dale describes the weather as polarizing, where individuals either enjoy it or endure significant discomfort due to the extreme conditions.
