How Tom Hornbein’s 'Maytag Mask' Changed Breathing on Everest

How Tom Hornbein’s 'Maytag Mask' Changed Breathing on Everest

This week marks two years since Tom Hornbein’s death and 95 years since his birth — an apt moment to remember a climber whose technical innovation helped reshape high-altitude mountaineering.

Best known for the 1963 first ascent of Everest’s West Ridge and the mountain’s first full traverse with Willi Unsoeld, Hornbein’s legacy extends well beyond that historic climb. He applied his medical training to solve a practical problem that endangered climbers: inadequate oxygen masks at extreme altitude.

Facing a life-or-death equipment problem

On the 1960 American–Pakistan Karakoram Expedition to Masherbrum (7,821 m), Hornbein and his teammates discovered the limits of the period’s Swiss-designed masks — originally developed for Everest in 1956. The devices were hard to breathe through and prone to ice-clogged valves.

“When we got up high and put them on, we found ourselves ripping the mask off and gasping for air,” Hornbein later recalled.

Ice buildup in valve assemblies, high breathing resistance, and complicated multi-valve designs made those masks unreliable above roughly 7,000 m.

A clinical mind meets practical design

As a trained anesthesiologist and physiologist, Hornbein understood respiration better than most climbers. Rather than accept the status quo, he treated the failure as an engineering challenge. His solution was elegantly simple: a single-valve facepiece molded as one flexible unit of rubber that minimized resistance and eliminated the tangle of separate inspiratory and expiratory valves that tended to freeze.

The single-valve design reduced airflow resistance and used a flexible body that could be squeezed or cleared with a mittened hand if ice formed — avoiding delicate field repairs.

From idea to prototype: Maytag helps build the mask

Manufacturing was the main hurdle until a chance meeting with Fred Maytag — then recuperating at Washington University Medical Center, where Hornbein worked — led Maytag’s company to take on prototype production. Though better known for washing machines, Maytag’s research division produced molds and prototypes that turned Hornbein’s concept into a working device.

Field tests on Mount Rainier in 1962 and controlled trials in hypobaric and cold chambers showed markedly lower breathing resistance and easier de-icing compared with previous models. The device became known informally as the "Maytag Mask."

Proven on Everest and built into the future

When used on Everest in 1963, the mask performed reliably. Climbers reported it felt natural to breathe through and required little additional training. Its simplicity translated to dependability in extreme cold and high winds, solving what Hornbein described as problems of "high mask resistance and ice accumulation."

The Maytag Mask established core principles that persist in modern high-altitude oxygen systems: low breathing resistance, effective one-way valves to avoid rebreathing, and a flexible facepiece that can be cleared in the field. Later designs adopted lighter materials and refined valve arrangements, but many contemporary models (for example, those from TopOut or Poisk) still show a clear lineage to Hornbein’s prototype.

Legacy beyond the summit

After Everest, Hornbein enjoyed a distinguished academic career at the University of Washington, researching respiratory physiology and anesthesiology. He remained modest about his public profile — preferring not to be remembered only as the doctor who climbed Everest — yet his influence on both physiology and mountaineering technology endures.

Two years after his passing, it is fitting to recall not only the climber who stood on Everest’s West Ridge but the innovator whose practical, medical-minded solution helped others breathe easier as they headed for the roof of the world.