A rare amber health warning for "extreme heat" issued by the Met Office has now been extended from Sunday until Tuesday next week.

Temperatures are expected to soar into the mid to high 30s and there is even the chance Norfolk could see a record-breaking 40C in parts of the county.

The East of England is already in the midst of a level 3 health warning issued by the UK Health and Security Agency (UKHSA).

But could this rise to level 4 and a national emergency be declared?

Why is it so hot?

According to Weatherquest meteorologist Dan Holley, everything is "lined up" to cause a "severe weather event" in the region.

Mr Holley said: "We have had an extended period of very dry, drought-like conditions.

"This means all the energy from the sun goes into heating, not evaporating.

"In the summer we have long days with the sun at its strongest and temperatures don't cool down much at night.

"With temperatures expected to be equal or higher than average body temperature, the heat will impact fit people as well as vulnerable.

"All these factors combined mean that everything is lined up for a severe weather event and I wouldn't be surprised if the health warning is increased."

What does a level 4 health warning mean?

When a heatwave is severe and prolonged, it can leave health and social services under strain.

If the ongoing impact of hot weather is considered dangerous enough, a level 4 warning could be issued, which is considered a national emergency.

At this level, fit and healthy people are also at risk and not just the vulnerable.

Severe heatwaves can leave food, water and energy supplies, as well as transport, business and health and social care services impacted.

The threshold for a level 4 health warning is temperatures above 30C during the day and above 15C at night.

The latest forecast

Temperatures have dropped from where they were earlier in the week but only by a few degrees and things will heat up again by Sunday.

"Monday and Tuesday will likely see the peak, as this is when a hot air mass will arrive from the south" added Mr Holley.

"The exact heat levels will depend on factors like cloud cover and wind strength.

"Temperatures will drop into the high 20s on Wednesday and will return closer to average highs expected for this time of year.

"The high pressure will retreat to mainland Europe however, this is not far away.

"With this hot weather just across the channel, we could see it move back so there is a chance temperatures will return to higher levels but perhaps not to the same severity."