Even then, Stoov did not materialise overnight. It took another three years for Teun to find the courage to leave his job at a bank and see whether anyone else might want one.

He returned to the shed, gathered batteries, heating elements and whatever else he needed, then took his prototype into Utrecht by bicycle. His first customers were not furniture stores or design-conscious homeowners. They were restaurants with outdoor terraces and a very obvious problem.

Patio heaters sent warmth upwards and out into the open air, while the people sitting beneath them remained cold. A heated cushion placed the warmth exactly where it was needed.

Teun began knocking on doors and eventually sold around 20 of his early cushions. Selling them turned out to be the easy part. Keeping those handmade prototypes working through an entire Dutch winter meant spending countless hours with a soldering iron, repairing and refining them as he went.

It was a modest and slightly chaotic beginning, but it established the essentials of the Stoov product that followed: cordless operation, battery power and washable covers. After a year spent developing the electronics, construction and fabrics in-house, Stoov formally began taking shape around 2014.

Its name, fittingly, reaches much further back.

Teun explains that a stoof was a small wooden foot warmer once used in Dutch homes and churches. Hot coals were placed inside a box with holes in its top, allowing someone to rest their feet above it and hold onto a little warmth. Examples can still be spotted in old Dutch paintings.

It was a simple form of personal heating created long before radiators and reverse-cycle air conditioning encouraged us to think in terms of warming entire spaces. Stoov may use batteries rather than hot coals, but the underlying instinct is much the same.

There is also, Teun jokes, a particularly Dutch appreciation for finding the least expensive way to stay comfortable.

“We like to spend money, but in the cheapest way possible.”

That focus on efficiency has helped Stoov find an audience across Europe, although the reasons people buy its products differ from one country to another. In the Netherlands, saving energy has been a particularly persuasive argument. German customers were already familiar with personal heating products, but Stoov found more interest there in wellness and in creating something attractive enough to live with openly.

Australia presented a different challenge.

Teun pointed out that I had chosen to take our video call outside, despite it being the middle of winter. For someone in the Netherlands, where the colder months are associated with retreating indoors, that was evidence of a very different relationship with the seasons.

“The moment you get the opportunity to go outside, you take the call outside,” he says. “That’s a completely different way of thinking.”

Australia may be full of poorly insulated homes, but we also spend much of the year attempting to stay outdoors for as long as possible. That makes a portable source of warmth useful on both sides of the window. It might sit on the sofa while someone works from home, then move outside for dinner, a morning coffee or an evening spent refusing to admit it has become too cold.

The technology may do the warming, but Lisa’s job is to make sure the finished product does not feel like technology.

Before joining Stoov four years ago, Lisa studied fashion design and worked for a number of fashion companies. Over time, she became increasingly interested in where products came from, how they were made and the materials behind them. A later role with a knitwear producer took her to factories in China and India, where she learned more about fibres, textiles and dyeing.

It also sharpened her frustration with the speed of the fashion industry.

“I was fed up with reproducing every year the same T-shirt in a different colour,” she says. “I looked for something more sustainable, and textiles with a purpose.”

For Lisa, a Stoov product is defined by the balance between that purpose and its appearance. It has to keep someone warm, but it should also fit naturally into the way they already live.

“You don’t have to hide it,” she says. “You can enjoy it, you can cuddle it, still look pretty and be warm.”

Teun describes a similar ambition. Older heating products were often brought out when needed, then hidden in the bedroom or cupboard when visitors arrived. Stoov’s cushions and blankets are intended to remain in view, looking more like home furnishings than appliances.

The distinction matters. A heating product can be efficient, safe and technically accomplished, but none of that means much if it spends most of its life packed away.