50 deg C is nowhere nearly too hot, especially for a laptop CPU. Some of the latest web contents can be surprisingly CPU-heavy. Launch any graphics-heavy game or benchmark software and see what happens to your CPU temperature.
If it still concerns you, grab a can of compressed air and blow your heatsink fins clean with care. You don't want to overspeed your fans, or get dust where there really shouldn't.
Modern processors are designed to function for extended periods at much higher temperature than that. While higher temperature will shorten their life, they would still almost certainly last through their useful lifespan in most cases.
Back until late Pentium III days , 50 degC was considered excessive - Though that was before the days of integrated thermistor and thermal protection, and was presumably measured on the motherboard at a point near the processor, which was likely much hotter.