Yesterday morning snow blanketed the city. Today icy wind is whistling from the Hudson to the East River. Why are we bringing you this weather report? It’s the time of year when you should sauna. Take advantage of your gym’s, or the out-size River Rock beauty at Great Jones Spa (you free get access with an hour-long treatment), or pay $25 for one of the city’s scorching hot Russian baths.

The process is pretty straightforward: Go into hot room, sweat, leave—and repeat. But behind the practice of lolling about half nude (or completely nude if it’s a single-sex sauna) is a deeply held philosophy of detoxification—that our bodies eliminate “environmental and lifestyle toxins” when we heat up. To get more from a simple sauna experience than sweat, we sought out the expertise of Birgit Krome, a dynamo of the downtown cleansing world.

Krome bases her cleansing practice out of Nolita’s Great Jones Spa because of its killer sauna and cold plunge area set under soaring ceilings and skylights. Her popular detox services surround the dry sauna—and colonics (but that’s another post). “I have taught literally thousands of people to sauna,” says Krome, who studied cleansing methods with Ann Wigmore to Hanna Kroeger, North American detox pioneers.

So print this, laminate it, and take it to a sauna near you.

SAUNA BASICS

1. Find a comfortable place to spread out your towel and lie down in the sauna. Think day at the beach, minus the SPF. If you’re a beginner, find your perch on the lowest bench. Stay for 10-15 minutes, or until your heart starts to beat quickly.

2. Hoof it to the cold plunge. If your gym doesn’t have one, jump in a cold shower. If you really can’t take the cold, do it Kneipp-style and just plunge your extremities into the cold. “The key is to heat up then contract the blood vessels. In that process, the blood starts to circulate better and pump through the hair-fine little capillaries that normally going don’t get enough nutrient-rich blood,” says Krome.

3. Lie down and rest for at least 20 minutes. Replenish with lots of water or juice. Your heartbeat will slow and your lymph system kicks into detox mode. You will start to feel your head clearing. Oxygen goes to the brain, says Krome, and people who get “brain fog” will start to feel it lift.

Repeat the sauna cycle three times. That’s the German tradition, says Krome. “It’s pretty intense and you’ll feel like you got enough. I sometimes do four rounds. You detox deeper through the skin with each round.”

ADVANCED SAUNA SKILLS

Dry brushingTake a soft, dry body brush and brush your skin up from your feet toward your heart. “Dry brushing is great to do before a sauna or in between sauna cycles. It activates the lymph system, and its waste-disposal mechanisms, so you detox more,” explains Krome.

Castor oil applicationRub some super-gooey castor oil on your stomach just before you go into the sauna. (Wear one of Great Jones’ disposable swimsuits or a two-piece you don’t care about because castor oil stains.) As you sit in the sauna, the heat ferries the oil to the liver and colon, promoting a deeper cleanse, says Krome. (Maybe save this for off-peak time.)

Do you detox? Tell us about your practices, here!