Feeling the chill? These are the warmest materials for winter

As the cost of living soars and the colder weather sets in, heating your home might feel like another financial and energy burden at the moment.

While avoiding the heater completely isn't always practical, you might be looking to rely on it a little less.

Or you might just find that you're always freezing when you step out of the house in the cooler months.

A simple workaround to these issues is becoming a bit more conscious about the clothing you choose to wear indoors.

Dr Rebecca Van Amber, a senior lecturer at RMIT's School of Fashion and Textiles, debunks the common myth that some fabrics keep us warmer than others, and offers some tips on choosing clothing to keep you toasty this winter.

When it comes to warmth, all fabrics are equal (sort of)

Dr Van Amber says that while a lot of us think that certain types of fabrics are warmer than others, this isn't actually true.

"When you actually look at the science, the property of the fabric that has the most effect on how warm it is, is actually just how thick it is," she says.

"So for most people, whether you're wearing a polyester jumper or a wool jumper, if they're exactly the same thickness, they'll have pretty much the same insulating properties."

Why is this the case? Well, put simply, fabrics work by holding a layer of air next to your body.

"They basically trap the air next to your body, so the thicker the fabric, the better it traps the air," Dr Van Amber says.

That trapped air essentially functions as a "blanket of air" around the body. Your body heat is what heats the air, and that's what keeps your body warm, she adds.

It's worth keeping in mind that some fabrics are very thin and don't come in thick weaves.

Dr Van Amber says some thicker fabrics you could look out for are polar fleece, wool, acrylic, cashmere and flannel.

But isn't wool warmer?

You've probably heard the conventional wisdom that wool is great at keeping you extra toasty in winter. It brings to mind images of that thick, woolly jumper you might have in your closet.

"I think that sometimes there's some wisdom in the case of anecdotal evidence and stories about certain fabrics," says Dr Van Amber.

She explains that wool jumpers are not warmer because wool fibres are warmer than others fibres, but because the wool is well-suited to making thicker fabrics.

"Because of the way the wool lends itself to woolly, hairy yarn, it's been traditionally used to make thick, woolly jumpers."

There's a property of wool though that Dr Van Amber says does make it more beneficial over other fabrics when you're dressing to go outside.

"Wool really excels if you're wet. So if you get wet, wool actually does keep you warmer," she says.

While you might feel a bit uncomfortable in a woollen jumper that’s a bit wet, there are properties in wool that actually makes it release heat when it’s wet.

Dr Van Amber also says that if wool is a fabric that irritates you, wearing a silk layer underneath can help alleviate some of the discomfort.

So, which are the best clothes to buy?

The answer is actually quite simple: when you're looking for clothes that will keep you warm, focus on choosing garments that are thick.

The principle applies to pretty much every item, whether you're picking out socks, inner layers, jumpers, down jackets or tracksuits.

What's freeing about this principle is that it allows you to work with preferences you may already have around clothing, like selecting garments that are inexpensive or environmentally friendly.

One example of this is the puffer jacket — more expensive doesn't necessarily equal more warmth.

Puffer jackets with a polyester filament as opposed to down are often not only more environmentally friendly, but cheaper too, Dr Van Amber says. As long as the garment and filling is thick, you won't be sacrificing on warmth.

Not too thin and not too tight

Equally important to choosing thick fabrics is the act of layering clothing when dressing for warmth.

Dr Van Amber, who grew up in Minnesota in the United States, says that layering is the secret to keeping warm indoors.

"[Minnesota] is one of the coldest places ever. I remember growing up, you'd be wearing two pairs of pants over there – a pair of thermal leggings and then pants on top," she says.

"So this idea around layering – I think sometimes we forget that that's a really good option."

For example, she suggests that while in the home, layering a pair of thermal leggings under some tracksuit pants will keep you snug.

Here's a general guide for layering garments:

1. 1.Start with a close-to-skin base layer, like a thermal T-shirt or leggings. Thermal leggings typically have a "pile" on the inside (a soft, fleece-like lining), making them warmer than ordinary activewear tights.
2. 2.Then put on some "regular" clothes with a looser fit, such as trousers and a long-sleeved top.
3. 3.If you feel you need an extra layer, add a jumper.
4. 4.Add a thick or puffy coat when you head outside.

Something else to keep in mind with layering: ensure your top layer of clothing isn't too tight, Dr Van Amber says.

Not only would it be uncomfortable to pack on tight layers, but doing so reduces the thickness of the air that's close to your body.

"It's about holding as much air [as] close to your body as possible," she says.

She also points out that people shouldn't feel pressured to go out and buy a wardrobe of new clothes to wear indoors.

"I really encourage people to look in their wardrobes and house and see what they've already got. Can you layer up with what you already have?"

If you don't want to spend too much, consider buying just one or two pieces of clothing that will give you some extra warmth and comfort in the colder months ahead.

"If you've been thinking about getting a puffer jacket for years, maybe now is the time – or perhaps some thermal leggings, a scarf or a big fluffy jumper."