As perovskite solar cells approach maturity, commercially viable production processes are desirable but record efficiency perovskite solar cells from research labs are predominantly deposited by non-scalable methods [1]. In addition to scalability, stability is a challenge [2]. Therefore, this study analyses the thermal and photothermal stability of co-evaporated (FA_0.82,Cs_0.18)Pb(I_0.89,Br_0.11)₃ perovskite films through several imaging and characterisation methods. Samples have been encapsulated to avoid excessive exposure to atmosphere. Since the films are deposited on Indium tin oxide/Me-4PACz, the crystallisation and deposition procedures mimic those in full stack solar cells. The effect of 1000 hours degradation in 85°C, with or without light exposure, is investigated with optical microscopy, hyperspectral and normal photoluminescence imaging, X-ray diffraction, time-resolved fluorescence imaging and electron microscopy. As-deposited films are found to have both micro-meter sized optically transparent clusters, in addition to red-shifted bright photoluminescence spots with lower bandgap, both possibly caused by non-uniformities in elemental distribution due to a locally different substrate or spitting. While heat does not cause any significant growth of these clusters, the grain size of the heated sample is substantially reduced. The quasi-Fermi level splitting is, however, unaffected by the heating, while the lifetime is cut by half, compared to the non-heated references. The observation of reduced grain size is in conflict with other studies [3] and may point to different degradation patterns in vacuum processed compared to solution processed perovskite solar cells. In agreement with [3], we find that the combination of heat and light is detrimental with severe cation, but in our case also halide segregation. The Me-4PACz layer is still intact and some cubic and photoactive perovskite is still present, although with reduced quality. Transparent patches of δ-CsPb(I,Br)₃ perovskite are identified by X-ray diffraction, energy dispersive X-ray spectroscopy mapping and UV-vis spectroscopy in the heated-light soaked samples. Identification of other chemical compounds is not feasiable due to complexity of the segregation. We have evidenced a clear difference in degradation mechanisms between light and heat exposed samples and those kept in the dark, while the mechanisms themselves have not yet been elucidated at this point.