Warning issued to people who drink bottled water as hottest day of the year is expected

It's been cracking the flags and Brits couldn't be happier, but it's important to choose wisely when you are hydrating yourself in this heat.

Today is set to be the hottest day of the year so far, according to the Met Office, so there will be plenty of bottled water being passed around on this sunny Sunday - yet you might be better off pouring yourself a glass from the tap instead.

Some parts of the UK are set to bask in highs of 27C today (12 May) and you really ought to make the most of it, seen as though the weather is taking a turn for the worse in the afternoon.

Areas will enjoy a warm and humid morning, before thunderstorms and heavy rain are going to roll in and ruin everyone's summer vibe, the Met have warned. I mean, should we expect anything less in the UK?

Meteorologist Simon Partridge said: "The really warm air will probably be confined to southern and eastern parts of England, with temperatures expected to peak in central parts of the country at around 27C."

Three yellow thunderstorm warnings are in place for later today across the majority of Wales, parts of southwest and northwest England, Northern Ireland and Scotland.

The downpour is predicted to hit parts of England and Wales this afternoon, so if you've got some washing to get out on the line - make it snappy.

After you've sorted all your weather-dependent chores out, I can imagine you might want to refresh yourself with a nice cold bottle of water... but it might not be the best idea.

Don't get me wrong, chugging a bit of aqua isn't going to kill you, but new research suggests that the container it's in can have an impact on your health.

Bottled water might not be the best drink choice (Getty stock photo)

When drinking water from a plastic bottle, it's important to be wary of the 240,000 plastic particles found in the average one-litre bottle of water - whereas there is only thought to be an average of 5.5 plastic particles per one litre of tap water.

Also known as nanoplastics, they are linked to cancer, birth defects and fertility problems.

These particles happen to be much smaller than microplastics, which were previously detected in water bottles, according to new research by the University of Columbia after experts used lasers that analysed the particles from three popular brands of water in the US.

The danger with these nanoplastics is that they are so small that they can enter directly into blood cells and the brain.

The plastics used to make water bottles usually contain phthalates, which reportedly contributes to 100,000 premature deaths in the US each year.

And according to the National Institute of Environmental Health Sciences, phthalates are 'linked with developmental, reproductive, brain, immune, and other problems'.

Plastic particles can have a worrying impact on your health (Getty stock photo)

Study co-author Beizhan Yan, an environmental chemist at Columbia University’s Lamont-Doherty Earth Observatory, said: "This was not surprising, since that is what many water bottles are made of. PET is also used for bottled sodas, sports drinks, and products such as ketchup and mayonnaise.

"It probably gets into the water as bits slough off when the bottle is squeezed or gets exposed to heat."

When the temperature spikes, chemical bonds in the plastic begin to break down, causing all this nasty stuff to seep into the water inside our bottles - so it's even more important to be picky about your drinking vessel during a heatwave.

According to Simplex Health, 'the only guaranteed way to get pure water is through steam distillation by using a water distiller', as it is 'gently boiled to kill off viruses and bacteria'.