In addition to joining events, you can also reach out to other members who have set their “hosting availability” status to “wants to meet up,” meaning that while their couch is unavailable, they’re happy to meet for coffee or be a resource while you’re visiting their city.

Another digital stalwart is VirtualTourist.com, which offers tips and reviews from fellow globe trekkers and has been around since 1999. That means you’ll find a true online community, a deep well of people with whom to interact. Members have profiles that may include photos, their hometown, travel interests and where they’ve been. Each member’s travel tips are tied to his or her profile, and should you like what you read or have questions, you can message the user. Who knows, maybe you’ll even get together offline. Once you’re on the ground in a city, you can meet dozens of people at once by attending a cocktail hour, group run, or tour through the worldwide events site Meetup.com.

While meeting someone new is exciting and can be deeply fulfilling, such overtures must be balanced with safety measures. Even Couchsurfing, which refers to strangers as “friends you haven’t met yet,” has a page devoted to safety, warning members to trust their instincts (“If a person, situation or profile seems unsafe for any reason, move on. Don’t worry about seeming rude”) and know their limits (“Partying like a rock star might be fun, but it puts your safety and well-being in the hands of others”). For women, especially, the site advises being educated about your destination’s cultural and religious norms and to “be clear about your boundaries and don’t be shy about stating them.”

At the same time, Dr. Epley said most people are not interested in taking advantage of you. “The person who wants to take advantage of you wants to find you immediately,” he explained. It’s different when you’re the one who decides to initiate a conversation. “When there’s random selection, you don’t have that risk of being targeted,” he said.

Solo travelers are often told to keep friends and loved ones informed about where they’re going and when (including the time they expect to return), know which neighborhoods to avoid, and learn local emergency numbers. Additionally, consider registering with the nearest United States Embassy or consulate at Step.state.gov/step. This allows the embassy to reach you in an emergency (natural disaster, civil unrest) and family and friends to contact you if there’s an emergency.

You may also want to memorize words such as “help,” “police” and “fire” in the local language, and have a plan for how you’ll get back to your hotel anytime you’re out after dark. If you are in a place where there’s no mass transit or if mass transit is not safe at night, have the number of a taxi service with you. If you use Uber, make sure the photo of the driver that appears on the app matches the face of the person who picks you up. Also, the Uber app has a “Share my ETA” option that allows you to send someone your whereabouts and estimated arrival time. (Before I even get into a car I send the driver’s name, car make and my destination to a friend or family member.)

The fear of strangers has deep evolutionary roots. Do not, Dr. Epley said, disregard your intuition. “Our research does not suggest that you should talk to everybody that you meet or that you should have the volume turned up to 11 in all your social interactions,” he said. It’s just that for most of us, “the dial for engaging others seems set a little too low. Nudge it up.”