(Portland, OR) -- Hot temperatures return this week in Oregon and the US Forest Service is warning about increased fire danger. Moderately strong east winds are forecast for the region. There's already a Red Flag Warning for southwest Oregon, where the Flat and Anvil fires are burning. Increased fire activity is expected. The Forest Service is warning with the hot, dry, and windy conditions any fires will spread fast and they're asking people to be especially cautious to prevent fires.