It’s possible that I’m the last person on the planet to not be cognizant of forest bathing. On the off chance that others may be in the dark, I thought a bit of information on the subject would be of interest, especially to gardeners, who find little reason to be outside when the ground is frozen or covered with snow. Of course there are those who find plenty of reasons to be outside: crosscountry and downhill skiers, dogsledders, snowshoers, skaters — even runners. All take pleasure in pitting themselves against the elements. But for the rest of us, those whose cold-weather outside activities are limited to ambling along behind the dog for a few minutes or racing across the parking lot from car to shops, forest bathing could be a way to engage with the outdoors during the winter months.

Forest bathing is a rough translation of the Japanese term “Shinrin yoku,” which translates into “taking in the forest atmosphere” or “forest bathing.” Forest bathing means wandering quietly among the trees, immersing yourself in nature. Forest bathing is not a trek to identify native plants or observe ecosystems, nor is it a hike with a pace and specific destination. It’s a chance to absorb a forest’s energy by actively noticing sounds, smells and textures, to slow down our monkey minds. While the relaxation element of such a walk is evident, scientific studies have shown that other benefits are derived from airborne essential oils called phytoncides that trees emit. This chemical, which protects the trees from microbes, also boosts humans’ immune system functions. Levels of the stress hormone cortisol have also been shown to decrease in test subjects after a walk in the forest, when compared with a control group of subjects who engaged in walks within a laboratory setting. Forest bathing seems to mitigate excess stress, which can play a role in headaches, high blood pressure, heart problems, diabetes, skin conditions, asthma and arthritis, among many other ailments.

Stress hormones also compromise immune defense; the activities of antiviral natural killer cells are suppressed by stress hormones. Since forest bathing can lower stress hormone production and elevate mood states, it’s not surprising that it also influences immune system strength. In a 2007 study, men taking two-hour walks in the woods over a two-day period exhibited a 50 percent increase in levels of natural killer cells — the body’s disease-fighting agents. But benefits can be found with just a 40-minute walk in the woods a couple times a week, which would be more sensible when temperatures hover in the low 20s.

Lest you dismiss these claims as too New Agey, look back at century-old reports on the success of the so-called forest cure in tuberculosis treatment. In the mid-to-late 1800s, physicians Peter Detweiler and Hermann Brehmer set up sanatoriums in Germany’s pine forests, as did Edward Trudeau in the Adirondack forests of New York. All reported the benefit of the forest air; contrary to expectations, the results seemed to be magnified when the forest air trapped moisture. There was speculation among the physicians of the time that pine trees secreted a healing balm into the air, and now, with modern technology and superior laboratory testing available, the existence of an unseen airborne healer is actually measurable.

Forest therapy is so accepted that it has its own international organization — the Association of Nature and Forest Therapy, which offers programs and guided walks all over the country. Since this means that walks take place in climates even colder than ours, guides offer some tips for those who may want to try winter forest bathing, to get a dose of sunlight and fresh air. The first may seem ludicrous, given that we live in northern New England, but you need to dress warmer than you think you might. You aren’t moving fast enough to generate any heat, so warm boots, lots of layers, mittens and a warm hat are a necessity. At temperatures of around 20 degrees, a walk should probably last no longer than an hour or instead of appreciating your surroundings you’ll just be noticing the loss of sensation in your fingers and toes. You might even consider carrying some of those handwarmers that hunters carry.

A forest bathing walk can be enjoyed alone, but could also be an event to be shared with friends, one that leads to a blazing fire pit at the walk’s end. Be sure to put out some of those stadium seat cushions so walkers can sit in a warming circle on the cold ground.