We report a significant incidence of warm water immersion foot (WWIF) in a light infantry battalion during a field exercise. Four hundred soldiers belonging to this battalion were surveyed to determine the prevalence of the WWIF syndrome. One hundred forty-nine soldiers surveyed developed the WWIF syndrome. The affected soldiers had a wide range of disability, ranging from mild discomfort to the inability to ambulate. All soldiers had full recovery within 2 weeks of the injuries. Although the syndrome is self-limited, the loss of these soldiers from combat critically impaired the battalion in its mission. We present this report as a reminder that effective preventive measures should be taken prior to field exercises and deployments.