restart your device after every flight and try to put it next to something which emits cold air and keep it there. it might be a graphics and plane count too so make sure to turn them to the lowest setting
Turn all of your graphics to low, and if you have a phone case remove that. Also, if you’re doing long haul flights that fan will come in handy so your device doesn’t overheat. Hope this helps!
To add on to the others saying to turn down graphics and plane count, utilizing IF’s automatic low power feature (on the general settings page in IF) reduces heat by a good amount, it drops the frames per second (FPS) from either 30 or 60 (depending on which you’ve set it to) down to 10.
When you enable it, it’ll kick in when you’ve not touched the screen after a short bit
Since IF wouldn’t be trying to do as much, it reduces the amount of processing, which consumes less power, therefore results in less heat.
Try to use a mobile radiator fan :) I’m using an iPhone 12 with max settings (anti-aliasing off) and it’s really hot. Then I bought a Mag-Safe radiator fan online (just $15) and my device isn’t as hot as before. Cheap but useful!!!
A good trick to do is once at cruising altitude, lower your screen brightness and go into the cockpit and zoom into the ceiling. Lower graphics will reduce the heating of your device. It works for me