* Stay off the trains unless journeys absolutely necessary.

* Government says headteachers have final say if schools remain open.

* Don't use disposable barbecues in parks.

* Risk of road surfaces melting.

* Household rubbish collections start at 5.30am to protect workers.

* RNLI warning to teens not to jump into the River Thames.

* Even hotter on Tuesday.

Brentford is set to suffer record temperatures today, pushing towards 40c and 100F, making it hotter than parts of the Sahara and the Caribbean.

Thames Water said London was getting through its very limited water supplies very quickly during this extreme and unprecedented heatwave. Simple steps to make sure every drop counts include everything from reusing what is left in the paddling pool to water plants, to swapping the hose for a watering can, to letting grass grow a bit longer over the summer.

The RNLI lifeboat station has also warned people against jumping into the Thames, a dip in which is often seen as an easy way of staying cool. It is understood that the borough's schools will remain open over the next two days, however there are concerns that large numbers of people are planning to go into the river later today.

Lifeboat Operations Manager at nearby RNLI Teddington, Matt Allchurch, said: "When the weather is warm like it is at the moment there is a temptation to go into the river and we see people jumping off the footbridge

"It's important to know that you don't really know what you are jumping into when you jump from the footbridge.

"There could be all sorts of obstructions under the water, there could be boats passing under just as you jump or other swimmers below you.

"The other danger is cold water shock where the body takes an involuntary inward breath when you jump into cold water and that can result in 2 litres of water in your lungs which is instant drowning.

"If you do survive that, then the secondary measure of cold water shock is the loss of the ability to move your arms and legs because all of the blood from limbs goes into your core to protect your core.

"So we have lost people in the last few years, young people who are good swimmers, trying to swim across the Thames. Even in this warm weather we are having at the moment the Thames is really quite cold.

"If you are going to use the river, stay close to the edge in shallow water."

South Western Railway issued a travel warning, saying: "Following the Met Office extreme heat warning, customers should only travel if absolutely necessary on Monday and Tuesday.

"There will be an amended service & reduced speeds, with changes likely at short notice."

Leader of the council, Peter Mason said: "Heatwaves can be dangerous, especially for those with chronic health issues, older people and the very young. We are working to make sure anyone struggling with the heat is supported and asking our residents to check on older and vulnerable friends, family members and neighbours.

"There is a range of advice is available in the ongoing heatwave, including how to spot the signs of heat exhaustion and heatstroke, and when to get help. I encourage everyone to have a look and make sure they keep themselves, and others as safe and comfortable as possible during the hot weather.

"We have seen an increase in the frequency of very hot weather and heatwave conditions over the summer, with climate emergency contributing to this. It is therefore more vital than ever to build resilience in our communities, support vulnerable people and take bold steps to improve the borough through our climate action programme."

The Royal Parks is worried about the impact of fires on the landscape and wildlife. It said: "Cumulatively fire can do great damage to grassland habitats as well as ancient trees and other habitats. These habitats are of great value, and the fires also kill any wildlife trapped in the blaze."

It has found evidence of lizards, grass snakes, toads, frogs, newts and stag beetles killed in fires in Richmond, Bushy and the other Royal Parks.

Local people are reminded that BBQs and fires are not allowed in any of the borough's parks or open spaces at any time.

Ealing Council is supporting the London Fire Brigade as it works to prevent grass fires – which the capital is at more of a risk from during hot and dry weather.

Some of the most common causes of grass fires are barbecues left unattended, carelessly discarded cigarettes and matches, and glass bottles left on dry grass.

The top ways for keeping safe in the heat include:

*Look out for those who may struggle to keep themselves cool and hydrated. Older people, those with underlying conditions and those who live alone are particularly at risk

* Close curtains on rooms that face the sun to keep indoor spaces cooler and remember it may be cooler outdoors than indoors

* Use cool spaces if going outdoors, like parks with plenty of trees. Find out about more cool spaces available in London

* Drink plenty of fluids and avoid excess alcohol

* Never leave anyone in a closed, parked vehicle, especially infants, young children, vulnerable adults, or animals

* If you have to go outside in the heat, walk in the shade, apply sunscreen, and wear a wide-brimmed hat

* Avoid physical exertion during the hottest parts of the day

* Make sure you take water with you if you are travelling

* While swimming can be a nice way to cool off, do not be tempted to jump into the River Thames

If you feel dizzy, weak or have intense thirst and a headache, move to a cool place as soon as possible. Drink some water or diluted fruit juice to rehydrate. Avoid excess alcohol

If you have painful muscular spasms (particularly in the legs, arms, or abdomen), rest immediately in a cool place and drink electrolyte drinks. Most people should start to recover within 30 mins and if not, you should seek medical help. Call 111 if you feel unusual symptoms, or if symptoms persist

Call 999 if a person develops any signs of heatstroke as this is a medical emergency. Further information on heatstroke and heat-related illness are available on the NHS website -  https://www.nhs.uk/conditions/heat-exhaustion-heatstroke/