Inner-case temps are only somewhat important. Realistically you can run a computer fine in a 100+ degree Fahrenheit environment.
Most enthusiast cases (especially airflow optimized) can damn-near match case temp with room temps. 70 out 70 in, hardly ever an issue.
The only time problems occur are with flow restriction and temperature buildup. Air isn't very good at transferring heat and you can cycling effect when case-ambience gets too hot.
Air heats, transfers poorly, air heats more, transfers very poorly, air reaches scorching, nearly no heat transferred, components thermal throttle/shutdown.
This is mostly limited to 1) super dusty filters 2) laptops 3) enthusiast rigs within low-flow sound dampening cases.