A Conservative MP has claimed that people taking precautions during the heatwave are "snowflakes" and "cowards".
John Hayes, who was previously a government minister at the climate change department, suggested that fear of the heat was everything wrong with modern Britain and "the state in which we now live".
It comes as forecasts hit a record-breaking 40 degrees of heat on Monday and Tuesday, amid Met Office warnings that people should stay inside and avoid the sun.
But Sir John, a Brexiteer who voted against reintroducing Covid restrictions told the Telegraph: "This is not a brave new world but a cowardly new world where we live in a country where we are frightened of the heat.
"It is not surprising that in snowflake Britain, the snowflakes are melting. Thankfully, most of us are not snowflakes.
"The idea that we clamour for hot weather for most of the year and then shut down when it does heat up is indicative of the state in which we now live."
Sir John has previously been described as a climate change sceptic and recently contributed to a report calling for climate action to be delayed.
In a public information video released on Friday Penny Endersby, chief executive of the Met Office, said:
"The extreme heat we're forecasting right now is absolutely unprecedented.
"We've seen, when climate change has driven such unprecedented severe weather events all around the world, it can be difficult for people to make the best decisions in these situations because nothing in their life experience has led them to know what to expect.
"Here in the UK we are used to treating a hot spell as a chance to go and play in the sun. This is not that sort of weather. Our lifestyles and our infrastructure are not adapted to what is coming. Please treat the warnings we are putting out as seriously as you would a red or amber warning for wind or snow.
"Stay out of the sun, keep your home cool, think about adjusting your plans for the warning period."