Brits are advised to sleep downstairs tonight due to the hot weather, with temperatures reaching up to 34C. Sleeping downstairs can help individuals stay cool and avoid potential health issues caused by the heat. The Met Office forecasts a very hot and humid day in the south, with a yellow heat health alert across various regions. The hot weather is expected to continue overnight, making it uncomfortable for many. High temperatures can worsen asthma symptoms and lead to heat-related health problems. Stay cool and safe during this hot weather spell.