Britain faces a 'rise in deaths' during the week-long heatwave, Government officials said today as temperatures soar to 34C – making the country hotter than Barbados.The second heatwave of 2026 has begun as the UK Health and Security Agency (UKHSA) upgraded heat health alerts for four regions from 'yellow' to 'amber'.A static area of high pressure over mainland Europe is trapping warm air underneath - known as a 'heat dome' - and resulting in increasingly warm air for southern England.Meteorologists said there is a 40 per cent chance of beating the all-time June UK record of 35.6C, just three weeks after a new all-time high for May of 35.1C was set. The Met Office said conditions will be 'very humid and muggy' especially in the South both day and night - and it will therefore feel hotter than the May heatwave. There is also a chance of 'tropical nights', when minimum temperatures do not fall below 20C.While much of Europe is also entering a heatwave, in the UK there will be a North–South split as lower pressure close to the north-west will see showers continue.London, the East, South East and South West regions were placed under the amber alert, while the Midlands faces a yellow warning. There are no alerts for the North.These warnings run from midday today until next Tuesday at 8pm – although the Met Office forecast currently suggests the heatwave could last until at least Wednesday.The amber alert states that the areas covered are likely to see 'a rise in deaths, particularly among those aged 65 and over or with health conditions', while 'significant impacts are likely across health and social care services' due to the heat.Officials have also warned of 'indoor environments overheating, increasing the risk to vulnerable people living independently in community and care settings'. People enjoy the sunshine in St Paul's Churchyard at lunchtime in the City of London today A sunny afternoon next to St Paul's Cathedral in London today as the heatwave begins