Wrapping up warm really CAN help stop you catching a cold.
(Your granny was right. You can catch a chill from being out in the cold without your vest on. Staff at the Common Cold Centre in Cardiff took 180 volunteers and asked half of them to keep their bare feet in icy water for 20 minutes.
They found 29% developed a cold within five days, compared with only 9% in the control group not exposed to a chill.)