In spite of good display cabinet design and controlled operating conditions in supermarkets, temperature heterogeneity inside the display cabinets was observed. This heterogeneity is influenced not only by the design but also by the ambient condition which may vary due to the seasons and air conditioning of the supermarkets. This work was carried out to experimentally study the influence of the room temperature on the product temperature at different positions in an open refrigerated display cabinet. Then, a predictive microbiological model was used to study the influence of product temperatures on the microbial growth. The display cabinet was located in a test room in which the room temperature was controlled at 20°C, 25°C and 30°C. At steady state, the measured product and air temperatures for various positions were reported. Higher room temperature leads to higher the product and air temperatures in the display cabinet. This influence, more significant for the product located at the front, can be explained by the external air infiltration which increases the air temperature in the curtain. An estimation of Listeria monocytogenes growth at various product temperatures shows the high impact of temperature on the food safety.