My iPhone 14 Pro Max displays “iPhone needs to cool down” while the phone is physically cold. This issue started immediately after the latest iOS update. The warning disappears after pressing the side button once or twice.
iPhone 14 Pro Max
I’ve seen a few similar posts recently.
First step: Go to Settings/Battery/Battery Health and see what it says for Battery Health: It should say Normal. Then look at Maximum Capacity. It should be above 80%. If it does not say Normal or if the capacity is below 80% you need a new battery: iPhone Battery Replacement - Official Apple Support
It it is normal and above 80% contact Apple support directly: Contact Apple for support and service - Apple Support
And if you can, post back with the results, as it can help others with this symptom.
iPhone 14 Pro Max shows 'iPhone needs to cool down' when cold after update
