It's not exactly clear why Dahlia Yehia was in Nepal. Was she trekking? Did she want to volunteer to help earthquake victims?

But it is clear how her story ended. Yehia, a 27-year-old art teacher who worked in Austin, Texas, had left the U.S. in July. The last communication from her was a WhatsApp message on Aug. 6, when she was in Pokhara (a town not affected by the quake). She was staying with a man she'd met through the website Couchsurfing, whose slogan is "stay with locals instead of at hotels." (See box below for a look at Couchsurfing.)

Now police in Nepal have told the Washington Post that the man confessed to beating her to death.

The tragic story raises questions about the idealism of the millennial generation and the risks of heading off to an unfamiliar country. We spoke about these issues with Joel Charny, vice president for humanitarian policy and practice at the charity umbrella group InterAction, and Dr. Tom Kirsch, director of the Center for Refugee and Disaster Response at the Johns Hopkins University Bloomberg School of Public Health.

What was your reaction to the story of Yehia's death?

Charny: What struck me is this idea that the younger generation is so used to the regularity of transactions on the web that they're letting their guard down a little bit. The idea that you'd be in touch with someone on a website who's going to turn into your host in some far-flung country — it's almost like the reliance on technology is giving people a sense of safety that maybe they shouldn't really have.

Kirsch: Human nature is human nature no matter where you go. Everywhere you go you will find good and bad people. Without some kind of vetting process, it's a crapshoot whether you're going to meet the good ones or the bad ones.

I do all these radical things: canyoneering, climbing, backpacking. I would not go to a foreign country and stay on someone's couch I don't know. That would make me nervous.

Although it's uncertain if Yehia intended to volunteer, there are a lot of young people who want to go off to a developing country and help after a disaster.

Kirsch: It's very common to have people just get up and go. They have a name in the disaster world. We call them spontaneous volunteers. We often find the volunteers who spontaneously come have no [relevant] experience or skills. They can do more harm than good, sucking up resources like food and water.

So are these spontaneous volunteers better off staying home?

Charny: The message is not "don't be a humanitarian" but just "be more careful." Take thoughtful precautions. The key for me is making sure you're with some organized structure that can take care of you, that is willing to say, "Yes, we're responsible for your safety, we're going to make sure you have a good experience, we're going to make sure you're healthy and bail you out if you run into difficulty."

How can a volunteer make sure they're connecting with a group that will protect them?

Charny: Ask if the group has staff in the country. If you're staying with a local family, when was the last time [the organization] visited that family? Do they have someone in the country monitoring the host sites and how the volunteers are doing? I would say send me the names of five people who've been through your program in the last six months, give me their email addresses. If the organization responds quickly and constructively, that gives you a better sense of their overall professionalism.

Kirsch: I think it's mostly about history. What prior projects have they had, do they have grants or contracts from funding agencies like USAID or European agencies. And I would specifically ask: Can you send me a copy of your safety plan? And is there a security training program you have to go to? It can be as short as a few hours online or one week in person if it's a country with active warfare.

Any other advice for anyone thinking about a trip to volunteer or to trek?

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