The Mediterranean Sea is warming rapidly due to climate change, exposing marine ecosystems to increasing thermal stress. While Marine Heat Waves (MHWs) - prolonged and intense sea temperature anomalies - have been extensively studied, Marine Cold Spells (MCSs) - extreme cooling events that can also disrupt species distributions - have received far less scientific attention despite their ecological relevance. This study aimed to i) characterise the occurrence, frequency, duration and intensity of MHWs and MCSs along the Italian coastline, and ii) assess their potential role in documented Mass Mortality Events (MMEs) in benthic coastal marine communities. We integrated 15 years of in-situ temperature data from the ISPRA National Tide-Gauge Network with daily satellite-derived Sea Surface Temperature data from the Copernicus Marine Service, covering 31 monitoring stations along the Italian coasts. Thermal anomalies were identified, characterized and categorized according to Hobday et al. (2016, 2018), and then spatially and temporally correlated with recorded MMEs. The analysis revealed a consistent rise in sea temperature at all monitored sites, following a clear latitudinal gradient with stronger warming at higher latitudes. This warming trend coincided with a marked increase in the frequency and intensity of MHWs and MCSs over the studied period. Moreover, temporal and spatial overlap between extreme thermal events and MMEs was found, suggesting that both heat- and cold-related anomalies are pivotal drivers of the recent die-offs in Mediterranean benthic communities. Our findings underscore the urgent need to strengthen monitoring efforts and implement targeted mitigation strategies, as increasing thermal stress, both from heatwave and cold spells, continues to threaten Mediterranean marine biodiversity.  This study also provides a valuable framework for assessing biological risks in a context of ongoing ocean warming.