iPhone iPhone Gets Hot And Loses Signal: How to Fix It

Signal fades as the phone heats up, then returns when it cools. This page explains what it does, how to use it on an iPhone and which carriers it applies to.

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Why does this happen and how do I fix it?

This is documented, deliberate behaviour rather than a fault. Apple states that when the interior temperature exceeds the normal operating range, cellular signal might weaken as radios enter a low-power state. The phone is protecting its internals by turning down the transmitter, and weaker uplink power means a weaker connection.

iPhone is designed for ambient temperatures between 0 and 35 degrees Celsius (32 to 95 Fahrenheit). The same thermal protection also slows or stops charging and dims the display, so signal loss usually arrives alongside those symptoms — that combination is the giveaway.

The trap is that this creates a feedback loop. Weak signal makes the modem transmit harder, which produces more heat, which throttles the radio further. Breaking the loop means cooling the phone and reducing what the radio is being asked to do.

What should I try, in order?

1. Stop charging and take it out of direct sunlight. Charging while hot is the fastest way to make this worse.
2. Remove the case. Cases with metal plates or thick insulation both trap heat and attenuate the antennas.
3. Quit navigation, camera, hotspot and any game. These are the heaviest heat producers Apple names, and hotspot in particular keeps the transmitter at high power.
4. Turn on Airplane Mode for a few minutes if you do not need the phone. Silencing the radio is the quickest way to break the heat and transmit-power loop.
5. Once it is cool, connect to Wi-Fi and turn on Wi-Fi Calling so the cellular transmitter is not doing the work.
6. If it runs hot in normal conditions with nothing demanding open, that is not thermal management working correctly — get it checked.

Which carriers does this apply to?

Published for	any iPhone
Type	iOS setting
Good to know	Thermal management is built into iOS on every iPhone and cannot be turned off. It is not carrier dependent.

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