With temperatures forecast to be around 21C tomorrow (Saturday, 3 May) in London, the Royal National Lifeboat Institute is reminding the public to follow its lifesaving advice if they are near the River Thames.

Temperatures are expected to cool as we head into the Early May Bank Holiday weekend, but the lifesaving charity is reminding members of the public of the dangers of the river Thames.

Wayne Bellamy, Station Manager at Chiswick RNLI, said: "With the warm weather forecast this week, we want to remind everyone to stay safe when near the river Thames.

"Whilst the air temperature will be high, water temperature remains dangerously cold.

"If you get into trouble in the water, Float to Live; tilt your head back with ears submerged and try to relax and control your breathing.

"Use your hands to help you stay afloat and then call for help or swim to safety if you can. It's OK if your legs sink, we all float differently.

'In any emergency, call 999 and ask for the Coastguard."

The river's temperature is still very cold at 10 degrees. Anything below 15C can trigger cold water shock when entering water, and there are many invisible, submerged obstacles.

The river also handles a huge volume of traffic every day and the current is very strong.

A spokesperson for the Port of London Authority said: "The tidal Thames is a busy working river with a fast current and the tide comes in quickly. In the hot weather, the water can look tempting, but the tidal Thames is no place for taking a dip.

"If you want to swim outside, stay safe by enjoying designated pools or swimming areas."

There are four RNLI lifeboats stationed on the Thames and they're available to respond to emergencies 24 hours every day. If you see anyone in difficulty in the water, call 999 and ask for the Coastguard (or the Fire Service if on the non-tidal Thames).