One night as Chris Banting was undressing for bed, he was surprised when his wife Helen pointed out to him that the back of his right calf was a worrying scarlet colour.
'It was strange because I wasn't in any discomfort at all,' says Chris, 62.
'If you have an infection, you think you'd be in pain or running a temperature, but I felt fine.'
It was November 2007 and the busiest time of the year in his job as a charity fundraising manager, but he decided it was something he should get checked out.
In fact, Chris was suffering from cellulitis - a serious bacterial infection of the skin.
Left untreated, the bacteria can spread through the body and cause potentially fatal blood poisoning or an infection of the muscle, bone or heart valve.