Young people in Gloucestershire are being urged to carry condoms when they go out partying this Christmas.
Sue Reeve, from the county's primary care trust said: "Enjoying a drink at Christmas and New Year can lead to more than a hangover for the unprepared.
"It could lead to unwanted pregnancies and a host of sexually-transmitted conditions."
One of the main concerns is Chlamydia, which rarely shows symptoms, but if left untreated can lead to infertility.
"People often carry infections without knowing it - and, sadly, you can't tell who is infected just by looking at them; but a condom can protect you," said Ms Reeve.
"Young people who may be having sex for the first time are particularly vulnerable and we would urge everyone to ensure they carry condoms- even if they aren't planning to have sex."