In centuries gone by if you wanted to stay extra toasty on a cold winter's day, you might take a pull of whisky from the hip flask in your pocket.
More recently you could opt for a pocket warmer. This nifty device involved the use of lighter fluid and a flame, which you carried around in your trouser pocket. Nope, nothing could possibly go wrong in that scenario.
Fast-forward to 2016, and the subject of a successful Kickstarter campaign is a range of coats heated by technology a lot more sophisticated than trying to set your nether regions on fire.
British company Emel and Aris is raising funds to put what is claimed to be the world's first smart coat into production. In their design, lightweight polymers produce infrared heat energy which is absorbed by the skin to heat the muscles and increase the flow of blood.
The heat is transferred via discreet lightweight panels sewn into the jacket on the shoulders, sides and lower back, and connected to a slim battery located in a waterproof pocket that can also be used to charge your smartphone.
You might expect such a jacket to look like some sort of futuristic aluminium foil space suit from the Jetsons, but you'd be wrong. Designer Rana Nakhal Solset has come up with elegant, streamlined styles: for men, an overcoat made from a waterproof treated blend of Loro Piana cashmere and wool; and a lighter-weight raincoat in water repellent Loro Piana cotton, with a detachable vest. For women, a Loro Piana cashmere and wool blend wrap coat, and a more lightweight Loro Piana cotton classic trench coat.
It's another sign that high-tech is making inroads into haute couture; by 2025, it's likely that almost every item of clothing you buy will contain some type of embedded technology.
We've already got garments with media player controls embedded in the sleeve, and suits that can buy your coffee.
On the drawing board is a scarf that can detect whether you're annoyed. Yes, a team of researchers at the University of Maryland has collaborated with boffins from Microsoft to develop a scarf that can assist the wearer to determine their emotional state, whether sad, calm, happy, or excited. The scarf remains an idea, and we're yet to be convinced it's a good one.
Meanwhile, Tommy Hilfiger has teamed up with solar manufacturer Pvilion to launch a jacket equipped with water-resistant solar panels, to collect energy to charge your electronic devices. The panels are sewn onto the back of the jacket and can be easily removed (a key feature, because they are ugly). One of the front jacket pockets has a double USB port where you can charge two devices at once, making you the go-to for all your device-addicted mates. At $US599 ($785) the jacket is an extremely pricey hedge against a flat phone battery – unless, of course, i it happens to be an overcast day.