A strategy is introduced to achieve high-temperature phosphorescence using planar rigid molecules as guests and rigid polymers as host matrices. The planar rigid configuration of the guest molecules resists thermal vibrations, while the rigid host matrix enhances the guest's high-temperature stability. Doped materials exhibit ultralong phosphorescence, with afterglow times of 40 s at 293 K, 20 s at 373 K, 6 s at 413 K, and 1 s at 433 K. The phosphorescence performance decreases as the rotational ability of the guest groups increases. The strategy also enables the use of organic phosphorescence materials for identifying rescue workers and trapped individuals in fires. Organic phosphorescence materials with ultralong afterglow are promising for applications in information encryption, organic light-emitting diodes, anti-counterfeiting, luminescent sensing, and bioimaging. However, high temperatures reduce phosphorescence due to thermal molecular motion. The study demonstrates that a twofold rigidity strategy, combining rigid guest molecules and rigid host matrices, effectively enhances high-temperature phosphorescence. The doped material BCZ/PVP exhibits excellent high-temperature phosphorescence, with afterglow times of up to 40 s at 293 K and 1 s at 433 K. The strategy is universal, as other rigid planar molecules also show good HTP properties. The materials are applied in fire protection, where they can be used for identification in high-temperature and thick-smoke environments. The study provides a new approach for developing organic phosphorescence materials with high-temperature resistance.A strategy is introduced to achieve high-temperature phosphorescence using planar rigid molecules as guests and rigid polymers as host matrices. The planar rigid configuration of the guest molecules resists thermal vibrations, while the rigid host matrix enhances the guest's high-temperature stability. Doped materials exhibit ultralong phosphorescence, with afterglow times of 40 s at 293 K, 20 s at 373 K, 6 s at 413 K, and 1 s at 433 K. The phosphorescence performance decreases as the rotational ability of the guest groups increases. The strategy also enables the use of organic phosphorescence materials for identifying rescue workers and trapped individuals in fires. Organic phosphorescence materials with ultralong afterglow are promising for applications in information encryption, organic light-emitting diodes, anti-counterfeiting, luminescent sensing, and bioimaging. However, high temperatures reduce phosphorescence due to thermal molecular motion. The study demonstrates that a twofold rigidity strategy, combining rigid guest molecules and rigid host matrices, effectively enhances high-temperature phosphorescence. The doped material BCZ/PVP exhibits excellent high-temperature phosphorescence, with afterglow times of up to 40 s at 293 K and 1 s at 433 K. The strategy is universal, as other rigid planar molecules also show good HTP properties. The materials are applied in fire protection, where they can be used for identification in high-temperature and thick-smoke environments. The study provides a new approach for developing organic phosphorescence materials with high-temperature resistance.