Cabinet Minister Kit Malthouse warned transport services will experience “significant disruption” over the course of the two days, with temperatures expected to reach 40°C in some parts of the UK.
The government’s Cobra Commission, Mr Malthouse, told the BBC: “Clearly the carriers are telling people on Monday and Tuesday to travel only when absolutely necessary. Services will be significantly affected.
“For example, the heat has consequences for the track, which means that the trains have to run slower. There may be fewer services. People should be wary of disturbance.
“If they don’t have to travel, now might be a time to work from home.”
The minister said steps have been taken to ensure hospitals and ambulances that may come under pressure are prepared, while schools are being given guidelines to remain open.
Record high temperatures are expected to hit the UK over the next two days.
The heat is so extreme that the With Office has issued a red warning for the first time, indicating an “exceptionally hot period on Monday and Tuesday”.
The Chief Executive of the Met Office, Penny Endersby, said “climate change has led to such unprecedented severe weather events”.
Monday and Tuesday we will see a red warning over urban areas in England ranging from Surrey to Manchester and York.
The warning, in effect from midnight Monday to late Tuesday, read: “Exceptional, perhaps record-breaking temperatures are likely to be on Monday and then again on Tuesday. Nights are also likely to be exceptionally warm for the UK, especially in urban areas.
“This is likely to lead to widespread impacts on people and infrastructure.
“It is expected that temperatures will drop from Wednesday.”
The extreme temperatures prompted ministers to hold a Cobra emergency meeting on Saturday after meteorologists warned that lives could be in danger.
Meteorologists have given an 80 percent chance that the mercury will surpass Britain’s record 38.7C temperature in Cambridge in 2019, with the current heat wave reaching its peak on Tuesday.
Boris Johnson today skipped his second emergency meeting in a row, forcing Cabinet Secretary Kit Malthouse to cope with the record temperatures expected this week.
It comes after he famously missed five consecutive Cobra meetings in the lead up to the Covid-19 pandemic.
Mr Johnson plans to hold a lavish farewell party at his grace-and-favour mansion, Checkers, on Sunday.