The idea that warmth can soothe not just the body but also the mind is hardly new. Across countless cultures and centuries, people have turned to heat—whether through sweat lodges, thermal baths, or saunas—seeking relief from psychic suffering. Yet when Eva Hilland, a cognitive neuroscientist at Oslo Metropolitan University, began combing through the scientific literature in search of rigorous evidence that would justify prescribing heat as a genuine mental health treatment, she found surprisingly little.
"There are many knowledge gaps," Hilland acknowledged, describing the state of the research. But the studies that did exist struck her as sufficiently encouraging to warrant further investigation. "So we just saw the potential," she said, explaining what motivated her to dig deeper into a field that remains largely uncharted.
That potential is now drawing serious attention as sauna culture experiences a resurgence. Once largely confined to Nordic countries, sauna-going—often combined with cold plunges or winter swimming—is attracting a new generation of enthusiasts from the United States to Norway, a country where sauna traditions run deep and where Hilland conducts her research.
The growing popularity of saunas as a wellness practice has outpaced the science behind their mental health effects. While researchers have developed a reasonably solid understanding of how sauna use and other forms of heat exposure challenge and condition the cardiovascular system, the picture is far less clear when it comes to the brain and mental wellbeing. That gap between popular enthusiasm and scientific certainty is precisely what Hilland and other researchers are now trying to close.
The setting for this emerging field of inquiry was on vivid display in late September 2026, when sauna enthusiasts and researchers gathered in Oslo for the International Sauna Congress. Among the attendees was Tony Stepanow, who traveled from Finland—a nation where sauna bathing is woven into the fabric of daily life—to participate in the event. The congress underscored how sauna culture has evolved from a regional custom into a global phenomenon with a growing following.
In Oslo, the sauna revival is particularly visible. Along the city's harbor, just steps from the Opera House and the Munch Museum, sits Sukkerbiten, a cluster of small saunas operated by the Oslo Sauna Association. The pier-side installation features saunas in a variety of styles, offering bathers the chance to alternate between intense heat and the bracing waters of the fjord—a ritual that devotees describe as both physically invigorating and mentally restorative.
That combination of heat and cold, and the sense of community that often accompanies it, is part of what has fueled sauna's appeal. But anecdotal reports of improved mood and reduced stress are not the same as clinical evidence, and researchers like Hilland are careful to distinguish between the two. The question they are pursuing is whether the subjective benefits reported by sauna users can be confirmed through controlled studies—and whether heat might eventually serve as a legitimate, evidence-based intervention for conditions such as depression.
The stakes are significant. Mental health conditions affect hundreds of millions of people worldwide, and existing treatments, while effective for many, do not work for everyone. If heat-based therapies could be shown to provide even modest benefits, they might offer an accessible, low-cost complement to conventional care. Saunas are already widely available in many communities, and unlike pharmaceutical interventions, they carry few risks for most people.
Yet the research remains in its early stages. Hilland's review of the literature revealed a patchwork of small studies and inconsistent methodologies, making it difficult to draw firm conclusions. Some findings hint that heat exposure may influence mood-regulating systems in the body, but the mechanisms are not well understood. Nor is it clear how much heat, delivered over what duration and at what frequency, might be needed to produce meaningful effects.
Scientists are also grappling with basic questions about how to design trials that can isolate the effects of heat from other factors. Sauna sessions often involve social interaction, relaxation, and time away from daily stressors—all of which could independently improve mental wellbeing. Teasing apart the specific contribution of heat itself requires careful experimental design, something the field has yet to standardize.
Despite these challenges, the momentum appears to be building. The International Sauna Congress brought together researchers, practitioners, and enthusiasts, creating opportunities for collaboration that did not exist before. Hilland's work is part of a broader effort to move the conversation beyond folklore and anecdote toward rigorous investigation.
For now, the evidence supports cautious optimism rather than definitive claims. The belief that heat can heal the mind has deep roots in human experience, and modern science is only beginning to test whether that intuition holds up. As saunas multiply along waterfronts and in gyms and spas around the world, the question of whether they can do more than relax the body—whether they might actually treat the mind—remains open, but it is no longer being ignored.
(0)