..since that warning was introduced in 2021

It was introduced given the increase in temperature. This is the first time in recorded history that the temperature in the UK has been forecasted to reach 40°C

To be fair they have been monitoring deaths before [0], just the first time there's a national warning to the public.

Quite a few schools have decided to use this warning to close as they are unable to manage heat on their premises [1]

[0] https://www.gov.uk/government/publications/phe-heatwave-mort...

This will be the hottest temp ever recorded in the UK though.

The hottest temperature by a couple of degrees. That’s a ridiculously large jump.

Most of the danger to life is people drowning in lakes, rivers etc.

British people are not normally found in lakes or rivers. If they are being driven into those dangerous environments by the weather, perhaps the weather could be considered dangerous.

According to the Romans it's common to find them there:

> Their form of rule is democratic for the most part, and they are very fond of plundering; consequently they choose their boldest men as rulers....They can endure hunger and cold and any kind of hardship; for they plunge into the swamps and exist there for many days with only their heads above water, and in the forests they support themselves upon bark and roots, and for all emergencies they prepare a certain kind of food, the eating of a small portion of which, the size of a bean, prevents them from feeling either hunger or thirst

https://penelope.uchicago.edu/~grout/encyclopaedia_romana/br...

It's historical writing so it must be true.

This is fantastic. I'm assuming that "a certain kind of food, the eating of a small portion of which, the size of a bean, prevents them from feeling either hunger or thirst" was Kendall Mint Cake.