All too often, winter holidays are ruined by illness but there are ways to help in keeping your family on their feet. Infections follow seasonal patterns. The Norovirus bug, which affected thousands last year, is also known as the winter vomiting virus, and those that cause flu arrive from other parts of the world in early December.

Colds and coughs also increase during winter. A current theory is that chilly noses may be the culprits. Cold air constricts the blood vessels, and as it is these that carry the white blood cells so vital for fighting infections, covering your nose with a scarf outdoors could help.

The run-up to Christmas, with its parties, late nights, booze and erratic diet, also affects the immune system. Adrenalin, the body's fight or flight reaction, can keep you going, so you only feel rotten when you finally stop.

Keeping healthy

Start protecting yourself, the earlier the better, but ideally by late November if you can.

• Plan ahead. Cook some dishes in advance and freeze. Ask the family to help, and if you are feeling a bit under the weather try shopping online.
• Support your immune system with a healthy diet and plenty of sleep – try to make up any hours lost to late nights.
• Be strict on hygiene at home and at work. Wash hands often, using soap, especially after coughing, sneezing or using the loo, as well as after touching door handles or phones. Clean phones, remotes and keyboards regularly with antiseptic wipes.
• Keep hands away from your face, and always wash them before eating, even a snack.
• Don't share towels used on hands and faces. Replace communal towels daily and run through the washing machine.
• Use tissues, or handkerchiefs that have been machine washed.
• If you do become ill, stay at home, especially if you have a tummy upset.
• Check your first-aid kit, and don't wait until Christmas Eve to buy medicines.
• Have a flu jab if you are in an at-risk group (see above right).

Jab time

The flu jab protects against the most common flu viruses predicted to hit each winter. These change yearly, so it has to be given annually. But it doesn't protect against colds and coughs.

Most people recover from flu fairly quickly, but it can be more severe for the over-65s, those with conditions such as diabetes, asthma or heart, lung or kidney disease, and anyone recently treated for cancer. For these, free flu jabs are available at GPs' surgeries and some pharmacies.

When illness strikes

When surgeries are shut you can get medical advice from your out-of-hours centre on your GP's answering machine. Or call NHS Direct on 0845 4647 – they can tell you about opening hours of chemists too.

A&E departments can get very busy so try to avoid them unless it's a real emergency.