It's true - we're more vulnerable to colds when we travel because we often leave home stressed out, arrive at our destination tired, eat irregularly, and many of us don't get restful sleep in hotel rooms. Many travellers catch a cold or the flu right after a long flight because the airlines don't introduce fresh air into the cabin as often as they used to. That means you're breathing recycled air filled with everyone else's germs.

Here are my tricks for staying healthy:

• Two days before a long flight, I begin taking the herbal extract Echinacea. Easily available at all health food stores, this flower extract is thought to build up the immune system.
• I found a way to avoid breathing the airborne germs in the recycled air on airplanes. No, I don't hold my breath! Savvy travelers, including many pilots and airline attendants, use a tiny portable air purifier, so I bought one too. And I haven't been ill after flights since using this little gadget.
• Airborne bacteria can enter your system more easily if you have dry nasal passages, which can occur if you're spending time in dry, air-conditioned airports, airplanes, hotels or offices. Years ago my doctor suggested I use a saline nasal spray on the plane. Works like a charm!