The cityscape of Budapest, as lights turned off at landmarks to reduce energy due to a power crisis in Budapest, Hungary, August 5, 2026. The warning indicated a potential health emergency with prolonged high temperatures posing a serious health risk to the entire population. Tourists walk past the Central University Library Carol I that has its architectural outdoor lighting turned off, in Bucharest, Romania, August 5, 2026. Dodging the heat in a cool caveIn Bosnia, tourists have taken shelter in the constantly cool temperatures of the UNESCO-listed Vjetrenica cave to escape outside temperatures of 40°C. Numbers allowed to visit the cave are limited because of the sensitivity of the environment.