When the Runway Meets the HVAC System: How Thermal Engineering Is Reshaping Fashion

There is a moment in Rick Owens’s Spring Summer 27 menswear show at the Palais de Tokyo that has been replaying in my head. Paris was in the grip of a historic heatwave. Forty degrees. A thousand excess deaths. The city’s mortuaries overwhelmed. And onto the runway walked models in ballooning Tyvek tracksuits, each one quietly humming, inflated from the inside by a small fan stitched into the lining.

It was absurdist. It was also, genuinely, a working garment.

The collaboration with Adidas brought the brand’s ClimaCool system onto the runway for the first time. Built for Formula 1 drivers and football players competing in extreme heat, the system pairs a frozen gel vest worn against the body with an insulating outer layer. The fan circulates air between the two. Adidas says the system can reduce skin temperature by up to 13 degrees Celsius and core temperature by 0.5 degrees, with endurance gains of up to 25 percent. Owens blew the silhouette up to Michelin-Man proportions and made the whole thing from Tyvek — the nonwoven high-density polyethylene fabric normally reserved for hazmat suits and construction site wrapping. Light, tear-resistant, and just porous enough to breathe.

The result sat somewhere between couture and civil engineering, which is exactly where the most interesting fashion is right now.

Air as a design material

The Adidas x Owens tracksuits were the loudest moment in a longer story building for two years. At the Milan-Cortina Winter Olympics in February, Nike introduced the Air Milano Jacket for Team USA. It is a garment that can switch from windbreaker to mid-weight puffer in 20 seconds, pumping air into a two-layer membrane via a small battery-powered fan. Nike chief design officer Martin Lotti described finding the right membrane as the critical breakthrough. “That jacket had an airbag within a jacket,” he told Dezeen. “Whereas now the airbag is the jacket.”

That distinction matters structurally. A conventional down puffer is a sealed system — the insulation is fixed, the warmth constant. An air-filled jacket is a variable system, adjustable in real time. From an engineering standpoint, you have shifted from passive thermal management to active thermal management. The garment is no longer a static object. It is a responsive one.

The origins of this idea are less glamorous than a Paris runway. Hiroshi Ichigaya, a former Sony engineer, invented the Kuchofuku fan jacket in Japan in 2004, designing it for outdoor construction workers. Two battery-powered fans sit at the hem. The semi-airtight fabric inflates around the body and circulates air across the skin. The silhouette was always ridiculous. The functional logic was always sound. For two decades it lived in hardware stores. Then climate change made it a fashion problem.

The crossover the industry didn’t expect

What has changed is not the physics. Air has always been an excellent insulator and coolant. What has changed is the urgency. Europe is now the fastest-warming continent on Earth. Designers are increasingly asked to perform in climates that conventional garment construction was not built for. The fashion week calendar has started to buckle under it. Owens moved his show to early morning to avoid the worst heat.

Owens’s collection went further than just the tracksuits. His foam-stuffed chaps were explicitly informed by Buckminster Fuller’s concept of tensegrity — the structural principle in which continuous tension and isolated compression hold a form stable without rigid connections. Applied to a garment, it means the shape is held not by the wearer’s body or a rigid frame, but by the distribution of stress across the foam elements themselves. This is structural engineering borrowed from architecture and aerospace, translated into a pair of trousers.

The detail signals something about the direction of travel. Fashion designers have always borrowed from architecture in terms of proportion and silhouette. What is different now is that they are borrowing from mechanical and thermal engineering. The garment is being treated as a system, with inputs — heat, humidity, movement — and outputs — temperature regulation, moisture management — that have to be designed around rather than ignored.

What the shape becomes next

The open question is whether this stays spectacle or becomes a design standard. Fan jackets have existed for 20 years without escaping workwear and niche outdoors retail. What Owens and Nike have done is demonstrate that the thermal engineering problem and the aesthetic problem can be solved simultaneously. A garment can cool a body by 13 degrees and still hold a point of view.

The harder question is what this does to the silhouette long-term. Every functional addition — fans, membranes, gel inserts — adds bulk, noise, and mechanical parts that fail. A garment with a battery pack is a garment with a battery life.

The design challenge ahead is not proving that thermal engineering belongs in fashion. Owens proved that, on a Paris runway, in 40-degree heat, while a thousand people were dying of it outside. The challenge is whether the industry can absorb the engineering constraints without abandoning the lightness and precision that makes a garment worth wearing in the first place.