The U.K. weather office says Britain has shattered its record for the highest temperature ever registered, with 40 degrees Celsius in London.

The highest temperature previously recorded in Britain was 38.7 C, a record set in 2019. The high Tuesday came as the country sweltered in a heat wave that also scorched mainland Europe for the past week.

Travel, health care and schools were disrupted in a country not prepared for such extremes. Parts of England are under a “red” alert, a warning for extreme heat that poses a risk of serious illness and even death among healthy people.

The high temperature in London reached 104 degrees on Tuesday, nearly 30 degrees warmer than its average summer high.