The UK's electricity system came under pressure on Wednesday as a severe heatwave increased demand for power across the country. The National Energy System Operator (Neso) took emergency steps to secure enough electricity and avoid supply shortages during the evening peak period. Industry data showed that Neso was expected to spend about £10 million to secure extra electricity supplies. This amount was more than four times the normal daily cost. The move came as households and businesses increased their use of electric fans and air conditioning units to cope with record temperatures. The UK Power Supply Crisis emerged as high temperatures spread across Britain and much of Europe. At the same time, low wind speeds reduced renewable energy production. These factors combined to place unusual strain on the electricity network during the summer months. Late on Tuesday, Neso issued a notice asking electricity generators to provide additional power. The operator warned that demand could exceed normal safety margins during Wednesday evening. It estimated that an extra 1,900 megawatts of electricity would be needed to keep the system balanced. The warning was later withdrawn on Wednesday afternoon after Neso secured enough supplies. Reports showed that the operator agreed to pay about £1,400 per megawatt-hour to obtain around 1.7 gigawatts of imported electricity from mainland Europe. The price was almost 20 times higher than average electricity prices recorded during June last year. A spokesperson for Neso said the situation was caused by extremely high temperatures across Great Britain and Europe, combined with low wind generation. The operator stressed that electricity supplies remained secure and that there was no immediate risk of blackouts. Power system margin notices are more common during cold winter periods when heating demand rises sharply. However, the recent heatwave created a different challenge. Demand for electricity increased during the evening as millions of people relied on cooling devices to stay comfortable. Electricity prices have risen across Europe during recent days. The heatwave has increased demand while also reducing power generation in some areas. Several power plants have experienced operational problems, adding further pressure to the market. On Tuesday evening, several gas-fired power stations in Britain received almost £4 million to generate electricity for a few hours. Demand increased as households turned on fans, air conditioners, and other cooling equipment during the evening. Weather conditions have also reduced renewable energy output. A large area of high pressure has trapped hot air across the region. While this has brought sunshine and record temperatures, it has also reduced wind speeds. As a result, wind farms have generated less electricity than normal. Elsewhere in Europe, power generation has faced additional challenges. Some nuclear reactors in France have produced less electricity because warmer river water has made cooling operations more difficult. This has limited available electricity supplies and contributed to higher prices across the continent. The combination of rising demand and lower generation has pushed wholesale electricity prices to some of their highest levels in years. Energy traders and grid operators have closely monitored the situation as temperatures continued to rise. Britain also recorded a new June temperature record on Wednesday. The temperature reached 35.8 degrees Celsius in West Sussex, making it the hottest June day ever recorded in the country. The heat has affected more than just the energy sector. Train operators urged passengers to travel only when necessary because high temperatures can damage railway infrastructure. Some schools across southern England and Wales closed temporarily. Hospitals also cancelled certain appointments due to the extreme weather conditions. Trade unions including the Trades Union Congress, the Bakers, Food and Allied Workers Union, and the Fire Brigades Union called for workers to take part in action during the hottest day of the year. The groups argued that stronger protections are needed for employees working in extreme temperatures. Current UK law sets a minimum workplace temperature of 16 degrees Celsius for office environments. However, there is no legal maximum temperature limit for workplaces. The issue has become a growing topic of debate as heatwaves become more frequent. The UK Power Supply Crisis highlights the challenges facing energy networks during extreme weather. Experts say that rising temperatures and changing weather patterns may increase pressure on electricity systems in the years ahead.