Imagine a day so hot that the ground beneath your feet starts to melt and the trains stop running. This is the reality facing millions of people this week as a dangerous heatwave hits the UK.

WHAT HAPPENED

A massive "heat dome" is sitting over Britain right now. Experts say this will push the heat to 40C. This is a level the country's old buildings and roads were not built to handle.

The Met Office has issued a red "danger to life" warning. They fear the heat will be so strong that roads may melt and train tracks could bend out of shape.

Schools across the country are already making plans to send kids home early. They want to protect students from the extreme heat inside classrooms that have no cooling systems.

WHAT THE EVIDENCE SHOWS

Temperatures are expected to hit a record 40C.

• A red "danger to life" warning is in place.
• Schools in many areas are planning early closures.
• Roads and train tracks are at risk of melting or buckling.
• Fatal electric shocks have been linked to "DIY AC" fan hacks.

THE BIGGER QUESTION

We often talk about the weather just to pass the time. But when the sun can break our roads and stop our trains, we have to ask a harder question.

Is our country ready for a future where these heatwaves happen every year? Our homes and tracks were built to stay warm, but now that might be what makes them dangerous.

WHAT HAPPENS NOW

Schools will start sending children home early to keep them safe from the peak heat. Commuters should expect many trains to be canceled or slowed down to prevent accidents on the tracks.

Health officials are also telling people to stay away from viral "life hacks" for cooling down. Using ice and water near electric fans has already led to tragic accidents.

WHAT WE STILL DON'T KNOW

How long will this heat dome stay over the UK?

• Will the power grid be able to handle the extra strain?
• How many homes will suffer permanent damage from the heat?