Acute kidney injury, which NHS guidance says is 'needlessly' killing thousands of patients, is a problem that affect patients who are already seriously ill in hospital.
Fiona Loud of the Kidney Alliance said patients with systemic illnesses were most at risk.
ITV News Science and Medical Editor Lawrence McGinty explains:
More top news
A protest against Black Friday sales, urging people to buy nothing at all instead, has attracted tens of thousands of supporters in the UK.
Republican presidential contender Donald Trump has been heavily criticised after appearing to mock a disabled reporter at a rally.
We currently have mild air for late November, but some cold air is on the horizon.