Before buying one, a couple of checks that often help more than the pad itself:

1. Find where the air goes in. Flip the laptop over: most draw air through vents on the bottom and blow out the back or side. A pad only does much if its fan sits under the intake grille, so match the fan layout to your vents rather than buying the biggest one. Even just raising the back edge by a couple of centimetres (a pad or a book) improves intake a lot.
2. Clean the vents and fan. Dust on the heatsink fins is the usual cause of a laptop getting louder over time. Compressed air through the vents in short bursts, holding the fan still so it doesn’t over-spin.
3. Check the video player isn’t decoding in software. If the fan only screams on heavier video files, that’s often a codec your GPU can’t decode (e.g. AV1 or HEVC 10-bit on older hardware) or a player with hardware decoding switched off. Watch CPU usage while it plays; if one or more cores are pegged, try enabling hardware decoding (in VLC or mpv it’s a setting) or a different player. That can cut the heat far more than a pad.