“Human beings are human beings—and that’s the wild card,” said Pivotal’s Siobhan McFeeney during a roundtable discussion at Fortune Brainstorm Tech in Aspen, Colo. on Tuesday. McFeeney serves at global leader, business transformation at the software company, but she was speaking about one of her passions, mountain climbing.

Having tackled Mount Everest multiple times—including a 2015 attempt that left her trapped in a cave-in—she told the group that she’s seen first hand how climbers will sometimes ignore all the data telling them it’s not safe to continue their ascent. “The tech is amazing, the data’s fantastic, but you still need to be able to rely upon yourself to make good decisions under pressure,” said McFeeney.

Teams and team dynamics are another place where human nature and technology intersect in important ways. When it comes to scaling an ice wall, McFeeney says she wants to know two things—the brand of equipment used and who else is involved. “I like to know the people on the team,” she said.

Fellow panelist and former professional cyclist George Hincapie agreed. Even with the best training, the best tech, and the best data, he said: “If you don’t put together a team that works well together and there’s not a good ambiance on the team, it’s not going to be successful.”

Technology can help with building strong teams, said Mark Verstegen, founder of human performance company EXOS. Consider fitness trackers and other tools that allow people to quantify and share their activity. “A cool part about data and data collection is that it starts a conversation—it gets people asking questions,” he said. “It’s engagement.”

Data also makes it possible to spot team members who aren’t pulling their weight, said Verstegen. “If there are two or three people who aren’t putting out the effort… You can’t hide anymore. We know everything.”