LIVES will be at risk unless people with minor ailments and injuries steer clear of casualty departments.
The new year warning comes from Dr Sohail Bhatti, director of public health for Huddersfield Central and South Huddersfield primary care trusts.
He said: "Accident and emergency departments and 999 services are exactly that - for emergency cases.
"People who use these services for minor problems may prevent others with life-threatening conditions from getting the immediate care they need.
"An emergency is a critical or life-threatening situation."
Dr Bhatti listed some of the circumstances in which people should seek urgent medical attention.
They include unconsciousness, heavy blood loss, suspected broken bones, deep wounds - such as a stab wounds - suspected heart attacks, severe breathing difficulties, chest pain and head injuries.
If the situation is less critical and people are unsure what to do, they should phone NHS Direct on 0845 46 47 or go online at www.nhsdirect.nhs.uk
NHS Direct is a 24-hour health advice line staffed by nurses and health information advisers.
It offers a range of information, from what to do if people are feeling ill to the opening times of ther nearest late-night pharmacy.
Dr Bhatti has also advised people on how to cope with sore throats, coughs, cold and flu symptoms.
"Many people go to their GP expecting antibiotics for cold and flu symptoms," he said.
"Colds and flu are caused by viruses. Antibiotics don't work on viruses, so they won't help you."
* Drink plenty of fluids (non-alcoholic).
* Cover your mouth when you cough or sneeze, to avoid spreading germs.
* Wash your hands regularly.
* Avoid strenuous exercise if you have flu.
* Ask your pharmacist what medicines you can buy to treat your symptoms.
Dr Bhatti added: "I would also like to remind people who have regular repeat prescriptions to check that they have enough medicine to get them through any holiday period and, if necessary, contact their surgery as soon as possible before that holiday to ask for a prescription.
"The out-of-hours GP services that cover weekends and holidays are there to deal with emergencies only, not routine issues such as repeat prescriptions."