The key to kicking cold-weather sniffles is right under your nose.

As soon as we start to feel that first tinge of frost in the air, we immediately reach for vitamins to boost our immune systems, desperate to avoid the winter swarm of colds and flues.

But popping a few Vitamin C pills on the first day of winter is kind of like going for a brisk walk and then thinking you can run a marathon.

Strengthening and maintaining a healthy immune system is a year-long project, a project that is crucial for maintaining your overall health and well-being.

Luckily for all of us, there are a few sure-fire ways to maintain your health and keep your immune system firing on all cylinders, no matter what the season is. And the best part of all? You can indulge in a lot of relaxing activities along the way.

Step One: Protect your sleep at all costs.

According to the National Sleep Foundation, adults aged between 26 to 64 years old should be getting between seven to nine hours of sleep each night. However, the average Australian adult is probably not hitting that sleep target every night, and if you’re looking at your clock right before bed and thinking “if I go to sleep right now I’ll get six hours and 55 minutes of sleep…” you are already behind the eight ball.

We already know that technology and caffeine can have a negative impact on our sleep, but did you know your temperature is just as important when it comes to getting in a proper snooze? And since you’re probably not ready to give up your phone for an entire night, ensuring your body is at the correct temperature for sleep is one of the easiest ways to keep your immune system kicking.

According to the National Sleep Foundation, your bedroom temperature should be between 15 and 19 degrees Celsius for optimal sleep. When lying in bed trying to snooze, your body temperature decreases to initiate sleep, but at the same time, having the room too cold can lead to restlessness and can also affect the quality of sleep.

Indulging in a cold or hot shower before bed will relax you and get your body to the right temperate for sleep. Placing a cold bowl of water in front of your fan will cool your room down, while wearing socks to bed will insulate your body heat while you sleep.

Step Two: Always treat yourself....just do it the right way.

If you’re anything like me, you live your life on a rewards-based system, meaning that you like to give yourself little “treats” as an incentive for getting through the day.

Things like snuggling up on the couch with a bowl of ice-cream and a book or relaxing with a glass of wine before bed may sound like a good way to practise a bit of self-love, but in reality they are actually causing long-term damage to your immune system.

A glass of wine may make you drowsy, but it can actually disrupt your sleep for an entire night and leave you feeling fatigued the next day.

So, how can you safeguard your immune system while also treating yourself after a hard day’s work? The answer is to swap comforting foods for relaxing activities where you can. Instead of wine or chocolate, opt for a warm relaxing bath, chatting with a friend or taking a long walk.

Your endorphins will go into overdrive and you’ll be left feeling healthier and happier all year round. And, if you’re still looking for a feel-good treat? Try a warm, calming cuppa as a way to wind down and relax at the end of a busy day. Nothing will sweeten your mood faster.

Step Three: Vitamins are your friends. There’s more than one way to hang with them.

A healthy, balanced diet is vital to boosting and maintaining a strong immune system, and the trick to sticking to a good eating plan is to keep it interesting. After all, variety is the spice of life.

Vitamin C is one of the biggest immune system boosters out there. In fact, if your body has a lack of Vitamin C you are much more prone to getting sick and will be unable to fight off infections.

While this news may have you reaching for the Vitamin C pills, or a dozen oranges, there are actually plenty of other ways to inject this immune booster into your diet.

Foods rich in vitamin C also include grapefruits, tangerines, strawberries, bell peppers, spinach, kale and broccoli. Basically, your plate should look like a cooked rainbow every time you sit down to dinner.

Your daily intake of vitamin C is essential for good health because your body doesn’t produce or store it, so by adding these items to your daily diet, your immune system will remain on a high.

Step Four: Your mental health is just as important as your physical health.

OK, this one may not sound as important as filling your body with fresh veggies or getting enough sleep, but you can't have a healthy body without having a healthy mind.

If you're working full time, or you have kids or family responsibilities to tend to, you probably don't get enough time to yourself. But setting aside just 30 minutes a day to do something just for yourself will see you more relaxed and fulfilled and better able to tackle the day and stick to your healthy diet.

After all, healthy winter immune systems are made in summer. So if your start looking after yourself now, you'll reap the benefits all year long.

What is your secret step to keep your immune system healthy this winter?

The opinions expressed in this article are the author's own.

Thanks to our brand partner Twinings and the New Twinings Defence Infusion.