We present our long-term photometric and spectroscopic observations of a high-latitude B supergiant with an infrared excess - the protoplanetary nebula IRAS 18062+2410. Our UBV observations in 2000-2006 have confirmed the rapid irregular photometric variability of the star with a maximum amplitude as high as 0.4m in V that we found previously. The B-V and U-B color indices vary with amplitudes as high as 0.10m and 0.25m, respectively, and show no clear correlation with the brightness. Our V-band CCD observations on 11 nights in 2006 have revealed brightness trends during the night. The variability of IRAS 18062+2410 is similar in pattern to the light variations in other hot post-AGB objects and some of the nuclei of young planetary nebulae. We assume that pulsations and a variable stellar wind can be responsible for the variability of these stars. In addition to the rapid variability, our 12-year-long observations have revealed a systematic decline in the mean brightness of IRAS 18062+2410.