Julia was 23 and working New York City’s streets to feed a drug addiction when Joyce Wallace, MD, pulled up in a van. Wallace, who runs From Our Streets with Dignity (FROST’D), tested her in the vehicle and discovered she had HIV. “The news mobilized Julia,” Wallace recalls. “She managed to get off drugs, get an apartment, take her meds, finish college and get her daughter back.” Today, with a master’s degree in social work and an undetectable viral load, Julia is 37, healthy—and a happy ad for getting tested.

Wallace has been testing sex workers since 1983. First she worked from her car, her baby on board to charm the women Wallace coaxed inside. Then she got a van, where she provided free counseling, testing, referrals and partner notification. Three more FROST’D vans now offer needle exchange, a drop-in center and primary care.

Challenging widespread opposing evidence, Wallace says, “We have definitely shown, year after year, an association between [unprotected] oral sex and [increased risk of] HIV.” Sex worker, pimp, John, man, woman, trans—all are welcome in FROST’D vans. “We go to people where they are,” Wallace says. “Some are so fragile, they’ve been rebuffed so many times, they won’t come and ask for help.”

If you’re selling sex on the streets, work with Wallace’s health and safety tips:

• Use a condom for all sex, including oral sex—even if you lose the John.

• If you shoot drugs and can’t get clean needles, reuse your own. Never share works—it spreads HIV and hep C. Wash your own with bleach and water. And…consider treating that addiction.

• Try to find safe, stable housing, especially if you’re positive. Treatment is hard to manage without a home base.

• Find an advocate. Call your local AIDS service agency. In New York City, look for a FROST’D van, go to FROST’D Primary Care at 369 Eighth Avenue, or call 212.929.6250.