Temperatures are expected to climb into the 30s on Wednesday as parts of the UK face water shortages and fires ahead of another heat wave.
A Met Office amber warning for extreme heat comes into effect for parts of England and Wales from Thursday to Sunday, with temperatures expected to soar to 35C, and even 36C in some places.
There is also a heat health alert from the UK Health Security Agency, with experts advising people to be careful of those who are older or have existing health conditions, as well as young children.
It comes as months of low rainfall and heatwaves have left parts of the UK facing drought, prompting garden hose bans and warnings about the impact on agriculture, rivers and wildlife.
Thames Water had to supply bottled water to residents of the village of Northend in Oxfordshire and pump water into the network, after the supply was cut off due to what it said was a problem technique at Stokenchurch Reservoir in Oxfordshire.
The company later said it had managed to “improve the situation” and that all nearby customers should now have water, but warned the pressure could be lower than normal.
“We continue to use tankers to pump water into the local supply network and work on other ways to increase supply to the region,” he added.
It comes after the company, which supplies water to 15 million customers across London and the Thames Valley, became the latest water company to signal it will ban garden hoses facing the hot and dry summer.
Three other water companies – South East, Southern and Welsh Water – have announced a ban on garden hoses for customers in the areas they supply.
Elsewhere, grass fires erupted as the heat and lack of rain left the countryside, parks and gardens dry, prompting people to refrain from barbecuing and a ban on disposable barbecues.
The Met Office says parts of England and Wales will see temperatures peak above 30C on Wednesday and reach at least 33C for four consecutive days from Thursday.
Temperatures are not expected to be as extreme as those in July which broke records when the thermometer soared above 40C in parts of the UK for the first time.
But climate change is making heat waves more intense, frequent and likely, with record high temperatures last month made at least 10 times more likely due to global warming and “virtually impossible” without it, research shows.
Scientists also warn that the likelihood of droughts is increasing due to climate change, driven by greenhouse gas emissions from burning fossil fuels and other human activities.