How to check CPU temperature on Raspberry Pi - Linux Tutorials - Learn Linux Configuration
ICE-Tower Low Profile CPU Cooling Fan with RGB LED for Raspberry Pi 4B/3B+/3B - OKdo
Amazon.com: GeeekPi PWM Fan for Raspberry Pi 4, Low-Profile CPU Cooler with RGB Cooling Fan for Raspberry Pi, Aluminum Heatsink for Raspberry Pi 4 Model B & Raspberry Pi 3B+ & Raspberry