"A cold nose may be one of the major factors that causes common colds to be seasonal," Prof Eccles explained.

"When the cold weather comes, we wrap ourselves up in winter coats to keep warm, but our nose is directly exposed to the cold air.

"Cooling of the nose slows down clearance of viruses from the nose and slows down the white cells that fight infection.

"Mothers can now be confident in their advice to children to wrap up well in winter."