Heat vulnerability in big cities is important because of the increase in heat wave frequency and thermal stress that is identified by Urban Heat Island. Our study investigated intra-urban heat vulnerability in Moscow, which strongly influenced by historic context in urban planning, with a focus on local disparities. We considered the vulnerability framework in terms of "exposure," "sensitivity," and "adaptive capacity," and adopted the concept of a 15-minute city to evaluate spatial patterns on example of 2021 heat waves. We used high-resolution meteorological data from the regional meteorological model COSMO-CLM and calculated the Physiologically Equivalent Temperature (PET) to assess thermal stress and define exposure. The data from OSM and other open sources were used to assess sensitivity and adaptive capacity through the proximity of green spaces, cooling centers, healthcare, and premium service facilities. The PET varied from 25.3°C in the outskirts to 30.2°C in Moscow centre; however, variations in thermal stress did not have adverse effects on the spatial patterns of vulnerability. The vulnerability indicator in the east was six times higher than in more prosperous areas of the center, north and southwest, due to historical development, mainly the transformation from former industrial areas into residential areas.