Particulate matter (PM) is linked to adverse health outcomes, yet the roles of specific PM components and their modification by extreme temperature remain unclear. We examined short-term associations between ten PM chemical components and daily mortality in Greater London (2015-2018). PM components include inorganic aerosols (black carbon from wood burning (BCwb) and traffic exhaust (BCtr), SO4, NO3, and NH4) and organic aerosols (hydrocarbon-like organic aerosol (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more and less oxidized oxygenated OA (MO-OOA and LO-OOA)). We applied quasi-Poisson generalized additive models and weighted quantile sum (WQS) regression to estimate single-pollutant, multi-pollutant, and mixture effects, respectively, and included interaction terms to test effect modification by heat waves and cold spells. All ten components showed positive associations with all-cause mortality in single-pollutant models with stronger estimated risks for respiratory mortality, particularly for NH4, NO3, SO4. In mixture analyses, the WQS index was significantly associated with all-cause mortality (RR = 1.015, 95% CI: 1.006-1.024 per 25th-percentile increase) and showed a marginally significance with respiratory mortality (RR = 1.018, 95% CI: 0.994-1.042). MO-OOA and COA contributed most to all-cause mortality, while BBOA and BC Wood dominated respiratory effects. Heat waves consistently amplified respiratory risks in both single-pollutant and mixture models with little evidence for cardiovascular mortality. Overall, MO-OOA demonstrated harmful associations across outcomes, suggesting potential toxicity link to secondary atmospheric oxidation processes. These findings support source-specific control strategies and highlight the importance of accounting for extreme temperature in air pollution mitigation policies.