Two outbreaks of collective clinical symptoms occurred in January 2008 and November 2008 at a call center in Raon l'Étape (Vosges) and at an adjacent middle school. A descriptive study was conducted by the InVS Regional Unit (Cire) East to characterize and compare the health events that occurred at these two sites during these two episodes and to explore etiological hypotheses. A questionnaire was used to collect demographic, occupational, and work-related information, as well as data on symptoms and the nature of medical care received. Additionally, environmental surveys were conducted to measure air quality. At the middle school, no confirmed health events occurred during these periods. At the call center, 93 out of 350 employees reported at least one symptom such as headaches, fatigue, dizziness, difficulty concentrating, or nausea. No difference in the frequency or type of symptoms was observed between the two periods. Outside of these periods, similar symptoms had already occurred at the company among 49% of those affected. The majority of respondents reported working conditions deemed unsatisfactory. Environmental studies confirmed the poor indoor air quality at the company: insufficient air exchange, excessively high temperature, excessively low humidity, and carbon dioxide concentrations exceeding the comfort threshold. No external sources of pollution were identified. These episodes are similar to recent incidents of “sick building syndrome” that have occurred in mainland France within companies in the same industry. The Cire’s recommendations focused on bringing the air conditioning system up to code. (R.A.)