Emission from CT states in donor-acceptor compounds is sensitive to the solvent polarity and originates from the solvent-stabilized excited states of emissive conformers. We hypothesized that it may be possible to achieve RTP from higher-lying triplet states by accessing non-equilibrium conformers in the excited state in the solid state, where the interconversion barrier from one conformer to another must be overcome for excitonic coupling to occur. Based on this concept, we report two conjugated RTP molecules, PXZ-Nap and PTZ-Nap (Figure ) using phenoxazine (PXZ) and phenothiazine (PTZ) as donors, which have both been observed to show conformational dynamics under external stimuli, and a substituted naphthalene (Nap) as the acceptor. The decoration of a 10H-phenothiazine-5,5-dioxide unit on the Nap distal to the donor is anticipated to modulate the excited state dynamics and to accelerate the ISC process owing to the presence of the sulfur atom. We found that when the two compounds are doped in poly(methylmethacrylate) (PMMA) or 1,3-bis(N-carbazolyl)benzene (mCP) (1 wt%), RTP from higher-lying triplet states occurs due to a thermally activated excitonic coupling between different conformers. Moreover, the RTP quantum efficiency of the emitters doped in mCP (1 wt%) improved over 80-fold compared to that in PMMA. The photophysics at a higher doping of 10 wt% in PMMA films revealed that there exist aggregation-regulated intermolecular interactions that offer a route to modulating T 1 H and low-lying T 1 (T 1 L ). Finally, we have exploited the anomalous RTP behavior to produce a temperature sensor.