Background and objective. Warm exposure highly demands on thermoregulation mechanisms, which is based on effectiveness of the microvascular function. The associations between microvascular function and metabolism in warm environment have received little attention in the literature, whilst alterations of carbohydrate metabolism in the warmth are well established [1]. The purpose of this study was to explore the microvascular function in response food intake in warm environment, as compared with control. Methods. Twenty-four (12 females and 12 males) healthy, acclimated to warm environment and physically active participants were recruited. They participated in two sessions (warm: 31°C and control: 22°C presented in randomized order). The skin blood flow (SkbF) was measured before and after standardized food intake (FI) through the acquisition of perfusion signal by laser Doppler fluxmetry (Periflux System 5000) with local heating protocol. Results. Glycaemia was higher in hot environment as compared with neutral (P <.001 in men and women), in agreement with previous publications [2]. Blood pressure was not affected by warm environment and FI (all P >0.11). The SkbF was affected by the environmental temperature (all P <.001). The microvascular function was significantly affected by FI (all P <.007) with an attenuated both initial peak and plateau responses to local heating marked in control environment. Conclusion. These results indicate a competition between thermo- and glycoregulation in a warm environment to the detriment of glucose homeostasis. This project is likely to contribute to the understanding of the contribution of the exposure to the warmth in the physiopathology of diabetes. References: 1.Frayn KN, Whyte PL, Benson HA, et al. « Changes in forearm blood flow at elevated ambient tempera-ture and their role in the apparent impairment of glucose tolerance ». Clin Sci. 1989 ;76: 323–328. 2.Dumke CL, Slivka DR, Cuddy JS, et al. The effect of environmental temperature on glucose and insulin after an oral glucose tolerance test in healthy young men. Wilderness Environ Med. 2015 ; 26:335–442.