Summer has arrived with a bang. Here in eastern Australia, we're already reaching record-breaking temperatures.
Unfortunately, like many homes and workplaces, my office doesn't have any air-conditioning. So I'm forced to try and find other ways to keep cool. Fortunately our café does make a pretty fantastic iced-coffee ... but even that comes with its own downside. The dreaded brain freeze.
You all know the feeling - one minute you're slurping down that frozen drink or hoeing into an ice-cream; the next, there's that splitting pain in the front of your head. It even has a scientific name: Sphenopalatine ganglioneuralgia. Despite what it feels like, getting a brain freeze doesn't really have anything to do with your brain at all.
It's about what's happening in your mouth. When we eat or drink something cold really quickly, we change the temperature in our throat and at the back of our mouth.
This makes the tiny blood vessels in those areas shrink, letting less blood pass through. This reduces how much oxygen can be transported to our brain.
Our body's natural response is to warm those areas back up. The way we do that is by increasing blood flow. By expanding the blood vessels in our mouth and nearby areas, it helps push blood to those areas to warm up.
One study found that one of the blood vessels that increases in size is the anterior cerebral artery, which is found pretty much right behind our eyes. They think the change in blood flow, and increased pressure in our skull, is what causes the sharp pain we get with a brain freeze. Once the area warms up, and the blood flow returns to normal, the pain goes away.
Other scientists have another explanation. It's possible that the changes in temperature and blood flow might activate an important nerve called the trigeminal nerve. This activation of the trigeminal nerve sends a pain signal to your brain, even though the changes aren't occurring in the brain.
A brain freeze, although temporarily painful, isn't going to do you any harm. Instead, it's probably a protective mechanism that help make sure we keep a good supply of oxygen heading to our brains.
But there is one way to avoid it. The slower you eat or drink cold things, the less likely you are to experience a headache.
So, if you want to avoid brain freeze this summer, slow down and savour the moment.
Dr Mary McMillan is a senior lecturer at the School of Science and Technology, University of New England.