He was embedded with British explorer Levison Wood, who was attempting to walk the length of the Nile, according to Men's Journal, for which Power was covering the story.
"On Monday, Matt fell ill, lost consciousness, and died a few hours later," the outlet notes. Heatstroke is believed to be the cause of death.
His body of work -- which ranges from a travel essay on a Philippine shantytown that survived off a massive trash heap, to a feature on a young American drone operator stationed in Nevada who helped kill more than 1,600 people in Iraq and Afghanistan -- has been anthologized in textbooks and numerous volumes of Houghton Mifflin's "Best American" series.
Friends, colleagues and fans posted tributes to Power on Tuesday:
Power grew up in Middlebury, Vt., but lived in Brooklyn, N.Y. He felt that having rich life experiences was in some ways more important than material wealth.
"The kind of stories I've gotten to do have involved fulfilling my childhood fantasies of having an adventurous life," Power said during a 2013 podcast for Longform, a website that finds and recommends compelling non-fiction writing. "Even though I don't make a ton of money doing it, I've never felt like I was missing out on something."
An autopsy is expected later this week.
Clarification: A headline elsewhere on the site has been amended to more accurately reflect the circumstances of Power's death.