Hоmirа is а 56-yeаr-оld wоman who presents with redness, warmth, swelling, and tenderness of her lower leg after sustaining a small cut while gardening. The area of erythema has expanded over the last 24 hours. Her temperature is 100.9°F (38.3°C), heart rate is 108 bpm, and laboratory results reveal leukocytosis. The provider outlines the border of the redness with a marker before initiating antibiotic therapy. Which clinical finding most strongly supports the presence of a systemic response to infection?