I've got three 4GB pi4's running. Two are in FLIRC cases which do an Okay job (and they look good :-) They transfer heat to the case and the Pi peaks out on my loads at about 55C. I've also got a cheap fan+heatsink solution (https://www.amazon.com/gp/product/B07TZQHXZ6/) which does a better job and keeps the Pi under 50C on all loads (it doesn't throttle at all).