The conduct of a perceived health survey is part of the epidemiological response to the industrial fire that occurred in Rouen in September 2019. This cross-sectional population survey, titled “A Study Listening to Your Health,” aims to assess the short- and medium-term health impacts of the accident, both physical and mental. This article describes the survey methodology. The area exposed to the accident, which covers 122 municipalities and is home to approximately 350,000 residents, was divided into four strata. Le Havre and its northern outskirts were designated as the control area. A simple random stratified survey was conducted to establish a representative sample of the population in both areas. Data were collected using a structured questionnaire. The first part of the questionnaire is primarily designed to describe exposures and symptoms experienced during the fire and in its aftermath. The second part focuses on the period at the time of data collection, one year after the accident. It includes a standardized instrument for measuring overall health, the MOS SF-12 (Medical Outcomes Study Short Form Health Survey). An additional questionnaire was administered during a second survey phase to assess the event’s impact on anxiety, depression, and post-traumatic stress symptoms. Data analysis will describe exposure to the accident, symptoms reported by the population, and the resulting use of healthcare services, and will estimate their prevalence in the population. Multivariate regression models will be developed to quantify, if it exists, the relationship between perceived environmental exposures and, on the one hand, post-accident symptoms, and, on the other hand, physical and mental health one year after the accident.