Your feet hit the dirt and the sound of cars is replaced by the call of a yellow warbler. The majestic trunks of Nordic pine and Tamarack shield you from the concrete. You smell the Ponderosas and let the huckleberry leaves brush your legs.

Exhale … and relax. It feels great … and it is.

Most of us know that getting out into nature is beneficial, whether it’s the exercise, clean air, vitamin D production, or simply taking a break from our frenetic daily lives, but science has discovered that visiting a forest has real, quantifiable health benefits. These can be both mental and physical, and extend beyond what most of us understand.

Medical ecology is the study of how interacting with the natural world affects human health. This includes the impact of climate change, pesticides and toxins, emerging infectious disease, and large scale environmental disruptions. It also includes a field called biophilia, which describes the health benefits of interacting with nature, including animals.

We’ve long known the mental health benefits of being in nature. Groups like Outward Bound and other Ecopsychology organizations have taken individuals and groups on backpacking and camping trips to deal with depression, anxiety, bipolar disorder, and addiction with great success.

This seems logical to us; we know that getting away from our stressors — our triggers — can help reorient our thinking and mood. But is there another way trees impact how we feel?

Consider this: Simply looking at trees reduces levels of cortisone and adrenaline, relieving stress and actually lowering heart rates and blood pressure. Spending time outdoors every day improves sleep.

Here’s more: Walking in a forest or park improves focus and memory. You are more likely to remember a string of numbers (and in the correct order) if you hear them when strolling in a park versus sitting at your desk. Some studies show that children who spend time in natural outdoor environments have a reduction in attention fatigue and children diagnosed with ADHD show a reduction in symptoms.

Researchers are investigating the use of natural outdoor environments to supplement current approaches to managing ADHD. Imagine prescribing a walk on Mount Sentinel instead of a stimulant to treat these conditions. And this all seems logical right? Avoiding the bustle of our daily lives and re-centering can account for much of these findings, but scientists have discovered more.

Trees (and other plants) release airborne chemicals that have a physiologic impact on us. These substances might impact the conditions mentioned above. But scientists know for sure about one group of these chemicals, called Phytoncides.

Phytoncides are natural antiseptics, fighting fungal and bacterial infections in plants. When we inhale them, they stimulate certain parts of our immune system, helping us fight infection as well, including cells infected with viruses. Some researchers are studying whether inhaling airborne molecules released from plants can help fight cancer.

One huge plus is that many of the benefits of being in nature occur even in urban green spaces, just in case you don’t have time to scoot out to the Bitterroots during your lunch break.

So get out there into the trees. Even five minutes among the Ponderosa, lodgepole and aspen or in green spaces will improve your health. Think of it as a prescription without adverse effects, and better yet, it’s free.

JoDean Nicolette, MD practices and teaches Family Medicine at Partnership Health Center.