<p>Fiber-reinforced composites (FRC) provide structural systems with unique features that appeal to various civilian and military sectors. Often, one needs to modulate the temperature field to achieve the intended functionalities (e.g., self-healing) in these lightweight structures. Vascular-based active cooling offers one efficient way of thermal regulation in such material systems. However, the thermophysical properties (e.g., thermal conductivity, specific heat capacity) of FRCs and their base constituents depend on the temperature, and such structures are often subject to a broad spectrum of temperatures. Notably, prior active cooling modeling studies did not account for such temperature dependence. Thus, the primary aim of this paper is to reveal the effect of temperature-dependent material properties—obtained via material characterization—on the qualitative and quantitative behaviors of active cooling. By applying mathematical analysis and conducting numerical simulations, we show that this dependence does not affect qualitative attributes, such as minimum and maximum principles (in the same spirit as <span>Eberhard Hopf</span>’s results for elliptic partial differential equations). However, the dependence slightly affects quantitative results, such as the mean surface temperature and thermal efficiency. The significance of our study lies in its contribution to a deeper understanding of thermal regulation systems in practical scenarios, offering valuable guidance and modeling tools for researchers and practitioners aiming to refine related designs. The novelty of our work stems from its comprehensive approach: developing a reduced-order modeling framework that incorporates temperature-dependent material properties, using experimentally measured thermal properties, and quantifying the impact of temperature dependence on both local and global thermal fields.</p>