DULUTH – It was 8 degrees below zero and the windchill was even colder, but Brittney Merlot wore a tank top inside the igloo-like structure next to Lake Superior.

"It's almost magical," Merlot said, as billowing steam collided with a wall of ice. The thermometer on the wall read 80 degrees.

A small business in Duluth built a rare ice sauna in early February next to its traditional wood-fired Finnish sauna in Canal Park. It was one of many ideas Justin Juntunen, founder of Cedar & Stone Nordic Sauna, lists when describing his dream to turn Duluth into "the sauna capital of North America."

Juntunen grew up in nearby Esko, where his family embraced their Finnish heritage by building saunas at their homes and cabins.

Saunas have become increasingly popular in recent years across Minnesota and the United States, particularly among millennials. A 2018 Mayo Clinic study links regular sauna use to a slew of health benefits, including reduced risk of heart disease, strokes and the flu.

"Science is backing up the things my grandma and grandpa used to say," Juntunen said.

He thinks saunas could be the next exploding trend, mimicking the booms of yoga and craft brewing. In addition to its Canal Park facility, Cedar & Stone also builds custom saunas for homes or businesses and sells curated sauna products imported from around the world (favorites include stoves from Estonia and bucket-ladle sets from Finland).

Juntunen, 35, went to college in the Twin Cities and got a job in higher education in the Pittsburgh area for a few years. He returned to the Duluth area in 2011 — but first he and his wife took a trip to Finland, with a list of public and community saunas on their itinerary.

"It's not just a sauna in somebody's backyard. It's this amazing business-oriented, community-center, coffee shop-esque thing," he said.

After returning to Minnesota, Juntunen spent years mulling the idea of launching his own sauna business. He quit his full-time job in August 2019 to focus his energy on Cedar & Stone.

The company, which now has 10 employees, is working to "raise the taste palate for quality sauna and quality heat," Juntunen said.

"We're not talking about a little warm room next to your gym or by the pool at your hotel," he said.

Juntunen said interest in custom saunas, which sell for $35,000 to $45,000 on average, has picked up during the pandemic as people look for new ways to relieve stress at their homes.

Cedar & Stone's traditional Finnish saunas run on low humidity and high heat, often between 160 and 200 degrees, sometimes higher. They emphasize that sauna is a process — a cycle of hot, cold, rest, rehydrate, repeat.

Appointments at Cedar & Stone's Canal Park location have started booking up since word of the ice sauna started spreading on social media. Juntunen and his team built the structure using 150- to 200-pound blocks of ice cut from Caribou Lake. It has a wood skeleton and roof over the cedar benches and wood-fired stove, but the ice exterior will eventually melt.

Juntunen drew inspiration from Finnish ice saunas built in the Arctic Circle. He has a laundry list of new sauna experiences he'd like to offer in Minnesota in the future — a sauna floating in the middle of a lake, a huge sauna like the community gathering spaces he saw in Scandinavia.

Cedar & Stone is exploring expansions into other parts of the state, but Juntunen said he's committed to Duluth for "decades to come." The city's natural beauty and Nordic roots, he said, make it a well-suited home for what he hopes is a resurgence of the tradition so beloved by his own family.

Katie Galioto • 612-673-4478