Building line downhill with fire below. Attempting frontal assault on fire. Unburned fuel between you and the fire. Cannot see main fire, not in contact with anyone who can. On a hillside where rolling material can ignite fuel below.
Weather gets hotter and drier.
Getting frequent spot fires across line. Terrain or fuels make escape to safety zones difficult. Feel like taking a nap near fireline. Know your capabilities and limitations. Wildland firefighting in its nastiest mode is difficult and hazardous.