Welcome to the home of

Australia's Warmest
Trackies & Jumpers

"Helping adventurous souls and comfort seekers to embrace the cold."

WINNER OF SHE-COM AWARD FOR ACTIVEWEAR

What an achievement in our first year of business! Our Original Sherpa Hoodie took out first place in the Women's Activewear Category.

See all the award winners here

Did you see us at the Gatheredsa Fashion weekend?

It was great to meet so many new and existing customers face to face at our stall at the GatheredSA - Adelady Fashion Weekend. Check out their website for more fabulous SA brands.

Gatheredsa website

FEATURED ON MAMAMIA - SEXY 6 with Mia Freedman

What did Mamamia Founder, Mia Freedman, think of our super-warm Thermal Theory hoodies and crews? We'll give you a hint - they were HOT HOT HOT!!!

TAKE ME TO THE VIDEO

FREE SHIPPING on ORDERS OVER $150

All our parcels are shipped out via Australian Post on the same day if ordered before midday. We offer Express shipping if you need a speedy delivery.

100% AUSTRALIAN OWNED SMALL BUSINESS

We know you like supporting the locals. Thermal Theory is a 100% Australian owned small business operating from Kangaroo Island, South Australia.

60-day Happiness Guarantee

We want our customers to enjoy our products as much as we do but if for some reason you are not happy we will offer a 60 day refund on return of product.

LOVE CAMPING BUT HATE BEING COLD?

There's nothing better than sitting around a campfire as the sun goes down. As it gets darker, the cold creeps in and the Thermal Theory hoodies and trackies come out.

They may look like a regular jumpers and pants but with a 12+TOG rating they are beyond expectations in comfort and warmth.

Our premium sherpa products are made from two layers of tech fabric designed to insulate your body. A heavyweight 550gsm cotton-blend outer layer, with a toasty brushed sherpa fleece lining on the inside.

You might have seen us at . . . .

ESSENTIAL SHERPA HOODIE

Updated colour range and premium embroidery.

SHOP ESSENTIAL HOODIE

ESSENTIAL SHERPA TRACKIES

Our track pants are legendary for their warmth and quality.

SHOP ESSENTIAL TRACKIES

ORIGINAL SHERPA HOODIE

Our base hoodie with all the features.

SHOP ORIGINAL HOODIE