Hundreds of patients have had hospital appointments cancelled after MRI scanners stopped working at one of the two UK hospitals which have declared a critical incident due to the ongoing heatwave.

The Norfolk and Norwich University Hospitals NHS Foundation Trust (NNUH) has declared a critical incident after heat and humidity affected the cooling systems required to operate its scanners. The trust said it currently has no functioning MRI scanners at its Norwich sites, including the main hospital and its community diagnostic centre. As a result, at least 254 outpatient appointments have already been cancelled.

Affected patients will be contacted directly by the truth and appointments will be rearranged "as soon as our scanners are functioning once more".