Amber alerts are issued in situations that could potentially put the whole population at risk.

The NHS may see increased demand on GPs and ambulances, for example.

Travel disruption is also likely.

In a post on social media, Cornwall Council urged residents to keep bedroom windows closed, wear multiple layers of thin clothing and, if eligible, get vaccinated against flu and Covid.

“Check on family, friends and neighbours who may be at higher risk of becoming unwell.

“If you are at higher risk, ask them to do the same for you,” it added.