Particulate-blocking firefighter hoods provide increased dermal protection from the carcinogenic and toxic by-products of combustion that are commonly found in soot and smoke. Firefighters need to be protected not only from the traditional hazards associated with the profession but also from new particulate hazards while remaining comfortable enough to perform their required jobs. The revised 2018 edition of the NFPA 1971, Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting, has set a value of 90% filtration efficiency for the optional particulate-blocking firefighter hoods. To achieve this efficiency, a particulate-blocking layer was incorporated into the hood. This additional layer can potentially alter the balance between particulate protection, thermal protection, and thermal burden of the firefighter hoods and present new challenges. Material-level protective performance and comfort properties were measured for traditional and particulate-blocking hood composites. The particulate-blocking efficiency of the composite materials were assessed utilizing ASTM F2299, Standard Test Method for Determining the Initial Efficiency of Materials Used in Medical Face Masks to Penetration by Particulates Using Latex Spheres. To determine the trade-offs associated with different composites, the thermal protective performance (TPP) was evaluated with ISO 17492 while the total heat loss (THL) was measured using ASTM F1868, Standard Test Method for Thermal and Evaporative Resistance of Clothing Materials Using a Sweating Hot Plate. This research provides data and insights addressing the relationships between particulate-blocking efficiency and the thermal protection and thermal comfort of both traditional and newly developed particulate-blocking firefighter hoods.