Timely public health interventions reduce heat-related illnesses (HRIs). HRI emergency department (ED) visit data provide near real-time morbidity information to local and state public health practitioners and may be useful in directing HRI prevention efforts. This study examined statewide HRI ED visits in North Carolina (NC) from 2008–2010 by age group, month, ED disposition, chief complaint, and triage notes. The mean number of HRI ED visits per day was compared to the maximum daily temperature. The percentage of HRI ED visits to all ED visits was highest in June (0.25%). 15–18 year-olds had the highest percentage of HRI visits and were often seen for sports-related heat exposures. Work-related HRI ED visits were more common than other causes in 19–45 year-olds. Individuals ≥65 years were more likely admitted to the hospital than younger individuals. The mean daily number of HRI ED visits increased by 1.4 for each 1°F (degree Fahrenheit) increase from 90°F to 98°F and by 15.8 for each 1°F increase from 98°F to 100°F. Results indicate that HRI prevention efforts in NC should be emphasized in early summer and targeted to adolescents involved in organized sports, young adults with outdoor occupations, and seniors. At a maximum daily temperature of 98°F, there was a substantial increase in the average daily number of HRI ED visits. ED visit data provide timely, sentinel HRI information. Analysis of this near real-time morbidity data may assist local and state public health practitioners in identification of HRI prevention strategies that are especially relevant to their jurisdictions.