✢ What makes a mole become cancerous?

Most moles are harmless and will look the same for many years. “Yet, in theory, all moles have the potential to change into a skin cancer,” warns Dr Perry. So it’s important to check even the ones you’ve had since childhood.

The majority of melanoma cases in adults are new moles, usually due to either long-term or short periods of overexposure to the sun. UVB rays penetrate less deeply and cause sunburn, while UVA rays go deeper into the skin, causing longer-term invisible damage. So if your skin has gone red, it’s a sign it has been damaged by too much UV radiation.

And it doesn’t have to be sunny for your skin to be at risk. “Even if you can’t see any blue sky, a significant amount of UV rays can still get through the clouds – even in the UK,” warns Dr Anjali

Mahto, consultant dermatologist and British Skin Foundation spokesperson. “You can even be affected indoors, as UVA radiation can penetrate glass, such as a car window or conservatory.”