The pressing threat of global warming poses significant risks to plant survival, adversely affecting their growth and agricultural productivity. It is crucial to understand how plants react to heat stress at the molecular level to develop crops that can withstand higher temperatures. In our study, we investigated the proteome dynamics of *Arabidopsis thaliana* seedlings under moderate heat stress conditions (30°C) using a combination of 15N-stable isotope labeling and the ProteinTurnover algorithm. This approach allowed us to closely examine the proteomic changes across different cellular compartments. Our findings revealed significant changes in the turnover rates of 571 proteins, with an average increase of 1.4-fold, indicating enhanced protein dynamics under heat stress. Notably, root soluble proteins showed more subtle changes, suggesting tissue-specific responses. We also detected significant turnover variations in proteins involved in redox signaling, stress response, and metabolism, highlighting the complex nature of these adaptive mechanisms. In contrast, proteins related to carbohydrate metabolism and mitochondrial ATP synthesis showed little change, underscoring their stability. This detailed analysis illuminates the proteomic adaptations of *Arabidopsis* seedlings to moderate heat stress, enhancing our understanding of plant thermal resilience and supporting efforts to develop thermotolerant crops.