A two-alarm brush fire near the 417 and Carp Road outside Stittsville is now under control.
The blaze began at about 4:30 Friday afternoon, stretching across an estimated 5 to 10 acres of land.
Bulldozers built up a perimeter around it.
Ottawa Fire's Marc Messier says several 10-to-20-foot high piles of old tree stumps were burning.
"We've got some heavy equipment in there. We've got to rip apart these piles and put out hot spots. They'll be doing that for a good part of the night, I would think."
A chopper was brought in to make water dumps.
Earlier, firefighters took the precaution of standing by near area homes.
Messier says the houses were in no immediate danger.
Five firefighters were taken to hospital as a precaution after exhibiting signs of heat exhaustion.