Have you ever wondered why mobile phones don't work the same when they get hot?
It's a scorching week in the UK and experts are predicting record temperatures.
The heatwave doesn't just affect people, but some tech too.
You might have noticed that mobiles can struggle when it gets warmer - whether it's the battery running out quicker than normal, it's going slower than usual or it crashes altogether.
It's because phones have no way of keeping themselves cool.
So, we've been looking into what happens to phones when things hot up.
Mobiles might go slower when they're hot, because they all have processors in them.
They're responsible for controlling everything that goes on in your smartphone and make sure it works properly.
The hotter the processor becomes, the slower your phone will run. This is because it has to reduce the power it's using to stop itself from overheating.
As well as the processor, lots of other things on your phone can make it heat up, including something as simple as its connection to a mobile data network.
All of these things can combine to make a phone slower if it's too hot.
Batteries are needed to power mobile phones.
They have chemicals in them which react together to make electricity. This reaction can also produce heat.
If it's a really hot day, then the battery can struggle to cool down when it's being used because of the extra heat.
If a phone feels a bit hot, experts say the best thing to do is to turn it off and leave it in a cool area for a while so it returns to room temperature.
Sometimes, it can help to remove the phone case.
Of course, keeping phones out of direct sunlight can avoid them getting too hot in the first place.
Putting it in the freezer isn't a quick fix because rapid temperature changes can be really bad for phones, so this isn't recommended.
What's more, if a phone is put in a freezer, the condensation can lead to water becoming trapped in it.
Lots of phones have a battery-saving mode on them too which can act as an effective cooling method.