If a book doesn’t help, you can try something more uneven. Try sticking four sockets from an egg tray on four corners of your laptop. Either you can stick them with a sticky tape/masking tape or use hook and loop tape for flexible design.
If you can’t afford/find a cooling mat, always prefer something hard under the laptop rather than something soft. For example, use a plastic casing, a lap desk, tray table or even a wooden cutting board to provide a solid, flat surface to allow proper airflow. Don’t use your laptop on soft surfaces such as a sofa, carpeting, folded quilt or pillow. Any vents located on the bottom of your laptop will be blocked and airflow will be reduced, causing it to overheat. It may even overheat enough to catch on fire.
