Start by clearing out any dust and applying high-quality thermal paste, such as Kryonaut or Conductonaut, to the CPU and GPU if your M15 R4 is overheating. You can also upgrade thermal pads and consider swapping in higher-performance fans (check compatibility, like with M15 R5 fans). Heatsink upgrades are harder due to model-specific designs. Lowering temperatures can also be achieved by modifying fan curves in Alienware Command Center and undervolting.