But in a patent published on Tuesday, Apple described the way iPhones are able to automatically power up and down, depending on how warm they get and how they are being used.
The idea isn't completely new, as the patent was originally applied for in January 2013. But it's interesting because it shows how Apple had made room inside its flagship device for something that controls the experience and feel of the phone, in addition to the usual software and hardware features.
The patent describes adding a temperature sensor to the iPhone, which would continually compare how warm the iPhone is to a maximum temperature threshold. If that threshold is reached, the iPhone would be able to cap its own power usage and cool itself back down again.
The idea is that this shouldn't stop you using the iPhone normally while it cools down. If you want to make a phone call or send a message, the power cap would lift until you're finished. But as long as the phone is hot, it will try to power-off as many functions as possible until you use it again.
Here's a diagram of the full process:
USPTO
It's not clear whether this particular patent is already in the iPhone or not, although a source inside the company tells Business Insider that new iPhones do have a thermostat mechanism that controls functions on the phone.