All burn surgeons recommend running cool water on the affected area for 20 minutes. You want to cool the burn to reduce the chances of more of the skin being damaged or injured in deeper layers. There are some caveats, though. For instance, if you have a small child with a large burn, putting them under cool running water for 20 minutes will make them very cold. The idea is to keep the rest of the patient warm, so wrap them up in a blanket or something similar, and only cool the affected area.

If you are worried about the burn, or if you have developed blisters or the skin colour has changed after you have cooled it down, lightly cover the injured area with plastic wrap, such as cling film. Then present yourself to a health service. In the UK, you can seek medical advice by calling 111 or, if the burn is severe, phone an ambulance.

If you have a burn injury, keep the area dressed and clean. Change the dressing regularly. With a minor burn that has injured the top layers of the skin only, and perhaps has blistered, the skin will take seven to 10 days to heal.

Andrew Williams is an executive committee member of the British Burn Association and a consultant burns and plastic surgeon at the Chelsea and Westminster hospital. He was speaking to Lucy Campbell.