A combination of cold weather and alcohol-related injuries are likely to mean a busier than usual festive period for ambulance crews, say bosses.
East Midlands Ambulance Service (EMAS) said it had increased resources to cope with a predicted upsurge in calls.
The service is urging people to stay indoors in difficult conditions and to drink sensibly.
Anyone with a non-urgent medical issue should contact their GP or NHS Direct before dialling 999, said a spokesman.
He said: "The key messages we would like to get over to the public are to avoid going outdoors unless it's necessary and if you have no choice, please take great care.
"And don't ruin your Christmas by drinking too much and ending up ill or injured, and never drink and drive."
He added: "Whilst we don't want to dissuade anyone from calling 999 if they need an emergency response, the public can really help us by only doing so in the case of a genuine emergency."
Where possible, anyone who needs to visit an accident and emergency ward should consider making their own way there, said the service.