In summary, two RTP compounds (PXZ-Nap and PTZ-Nap) have been synthesized. Both compounds possess complex conformational dynamics in the excited state, evidenced by the observed dual RTP. In doped PMMA films, we demonstrated that RTP emission from the T 1 H state originates from thermal activation between relaxed triplet excited state conformers. The photophysical studies in doped mCP films further support the observation that emitter-matrix interactions can modulate triplet-state emission. The F RTP in mCP from T 1 H was improved by a factor of 80.5 times to 16.1% compared to the that in PMMA. We ascribe this enhancement due to the improvement of RTP efficiency as a result of Dexter energy transfer from the T 1 of mCP to that of the guest emitters. Aggregation-regulated triplet emission was demonstrated because of enhanced intermolecular interactions as observed in the photophysical behavior at higher doping concentration in PMMA. This study provides a rare yet clear picture of the triplet exciton dynamics in conformationally flexible donor-acceptor molecules and shows how RTP can be enhanced as a function of host-emitter interactions. Given that we demonstrate that the relative populations of triplet excitons can be modulated as a function of the temperature, we demonstrated that these molecules could be used as functional temperature sensors for monitoring real-time temperature for COVID-19 vaccines during the ultracold chain logistics and storage.