Freelance journalist and travel writer Matthew Power, 39, died Monday while reporting in Uganda.

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.

Friends, colleagues and fans posted tributes to Power on Tuesday:

The loss to journalism of Matt Power is incalculable. And you didn't need to know him well to feel: here is an exceptionally good person. — Benjamin Kunkel (@kunktation) March 11, 2014

So heartbroken about @matthew_power. Known since he was a @harpers intern. Big heart, big smile, always fighting to tell the hard story. — Clara Jeffery (@ClaraJeffery) March 11, 2014

Awful news about the great writer and journalist @matthew_power. He was an early mentor and a guy I wanted to be. http://t.co/7HBrFZZD3C — Lucas Kavner (@Lucaskavner) March 11, 2014

.@matthewpower once climbed a tree dressed as a sunflower. To protest Giuliani, of course: http://t.co/ETs1gaLrOC I'll miss you, Matt. — Tim Stelloh (@timstelloh) March 11, 2014

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.