Fig. 2: Cows experienced high peaks of fever after H5N1 infection.

Body temperature was measured with an i-button intravaginal thermometer and recorded every 30 min throughout the experiment. Each data point represents the temperature measured at a given time by the device. Body temperatures are displayed for cows #1 (a), #2 (b), #3 (c), and #4 (d). The horizontal gray lines represent the normal temperature range for a healthy animal (100.4 °F to 103 °F). The gray shaded area represents the body temperature prior to infection.