New Zealand heatwave: Kiwis warned to drink less alcohol or risk hospitalisation

As New Zealand burns under a brutal heatwave, experts warn having a cold beer to cool down could do more harm than good.

The start of summer kicked off drinking season with Crate Day, an annual drinking event which takes place on the first Saturday of December.

Since then, Kiwis have been turning to alcoholic refreshment to help get them through the increasing temperatures.

But there is a problem - the alcohol interferes with regulation of water levels in our body, causing you to urinate more. As your body runs out of water, dehydration starts kicking in, causing headaches, dizziness and confusion.

The worst-case scenarios can be life-threatening - including heatstroke, seizures and hypovolemic shock.

Canterbury District Health Board medical officer of health Alistair Humphrey warns people need to look out for their mates if they've had too much alcohol, as it can lead to heatstroke.

"A lot of people that I've seen at the 24-hour surgery where I work have been coming in with headaches," he told Newshub.

"Sometimes their blood pressure... increases; sometimes they come in with dizziness; occasionally they have vomiting.

"Watch out for your friends. Many of the people I've seen are not necessarily aware themselves that they're getting dizzy or that they're getting overheated. But you should look out for your mates."

He says the most important thing is to stay well-hydrated and avoid too much sun.

"If someone's not wearing a hat and they're in the sun, or if you think someone's not drunk enough water - or, in particular, if you think they've had too much alcohol, because that will also dry you out - I think a bit of friendly advice can often stop someone from ending up in the emergency department."