Farms, humans struggling in Canterbury heatwave

Farmers are preparing for a long, hot summer as a sweltering heatwave continues to affect parts of the country.

But it's not just farmers who need to adjust - a scientist has told Newshub human bodies in New Zealand aren't prepared for this rapid heat change and many of us aren't coping.

Christchurch's Margaret Mahy playground is usually full to the brim on a Saturday afternoon, but this Saturday it was too hot to play at 31degC.

The slide got so hot on Friday, people were getting burnt.

Canterbury has had many days with temperatures above 30degC already in early December.

Farmers around the region are used to dry spells, but not this early.

"It gets a little bit drier and then all of a sudden you can be in quite a mess," says mid-Canterbury farmer Michael Salvesen. "It's dried up very quickly so it's caught everyone on the hop.

"The best thing to do is make decisions early and stick to them. If you destock too much, at least you will have good amounts of feed for what stock you do have left."

Thermoregulation expert Dr Nicholas Gant says human bodies are not coping.

"Our bodies are really struggling at the moment because the temperatures have increased so quickly," says Dr Grant.

"People become more fatigued, they become irritable, and when you're very hot your cognitive performance declines and your mood becomes terrible."

The way to adapt, he says, is actually not to avoid the heat.

"They should be getting out into it for manageable periods of time. Your body needs to be exposed to the heat stress in order to adapt, so doing some exercise is one of the best ways of doing that."

Having a cold shower at night is also recommended to aid sleep. But in Canterbury, that may soon not be advised.

Water usage in Christchurch is at an all-time high and the city council is warning if people don't monitor their use of water, restrictions could be imposed from as early as Monday.

While temperatures are expected to dip next week, the outlook for almost all the South Island is a drier December than usual.

On Sunday Canterbury will reach its 45th day without rain - the longest dry spell in the region since 1954.