What's the worst job to have in this scorching weather?

As the country continues to bake in the blistering heat, spare a thought for those whose jobs are made just that much harder by the hotter than average temperatures.

RNZ went in search of the worst job to be doing on a hot day.

Picture a prefab classroom with an old ceiling fan as the only means of cooling things down.

Then add some children made scratchy by an energy-sapping 30C day.

Could the job of a primary school teacher be the hardest job on a hot day?

A teacher at Christchurch's Banks Ave School, Belinda Walsh, said they would be adjusting things accordingly for the kids today, who were back for their first day of the new year.

"We wouldn't plan the sort of learning that requires a lot of deep thought in the afternoon.

"We would take regular breaks [and] remind children of the think, drink, learn policy we have at the school."

The quake-damaged school was due to move into new buildings with proper air conditioning - but not for another two years.

In the meantime they were making the best of things.

Another teacher, Adam Hastilow, had purchased a couple of fans for his classroom.

"I thought of bringing in a sprayer and spraying the kids down, I don't know if that's legal or not ... but we'll consider all options."

Down at the Good Habit cafe in a former convent in central Christchurch I find Kerim Hadfield still slaving away behind a steaming hot coffee machine, despite the hot weather.

"I think the end of the day, you've been working in it, the heat starts to hit you as it gets hotter and hotter as the day goes on. There are better places to be but this place is quite breezy with the doors wide open."

She agreed the grill was the hardest place to work on a hot day, which is where I find chef Jasmine Rabbett.

"I've got a nice breeze coming in now so it's alright ... you get used to the heat."

Surely nothing could top working over a gas stove top for eight hours a day as the hardest job to be doing in the heat? Well, actually, there is another line of work that tops even that.

Marty Duston and Stephen Cooke, who run a home maintenance business, carry out what must surely be the most exhausting job to complete when the sun is beating down.

Mr Cooke said laying down insulation inside ceilings on a hot day was his least favourite part of the job.

"[It's] dusty and I'm not too good with the fibreglass."

Marty Duston, said with new rules requiring homes to be insulated, a lot of their summer would be spent sweating it out inside people's ceilings.

"Even on a semi cold day you could do probably an hour and then you've got to get out of the ceiling space and get some fresh air and have a drink and then go back up and carry on."

Despite the heat, both men said they loved their jobs and wouldn't trade them in for a nice air-conditioned office.