A man filled a bucket with boiling water during a smoko break and "calmly" poured it over the back of a colleague's head, neck and shoulders.
Kian-Wee Show then sat down and continued eating his lunch while his victim jumped up and ran to the first aid room.
Show, a 28-year-old Malaysian national on a work visa, pleaded guilty to a charge of wounding with intent to cause grievous bodily harm.
He was sentenced to five years and seven months in jail yesterday when he appeared in Napier District Court.
The incident happened in the staff cafeteria of the Turners and Growers packhouse in Whakatu, near Hastings, on July 25 last year.
Show was sitting at a table with friends eating and drinking.
The cafeteria was full of workers that morning. The victim was sitting about five metres away, the summary of facts states.
Show walked towards the coffee machines, picked up a brown plastic bucket and kept walking towards a boiling water dispenser further along the bench.
He part-filled the bucket with boiling water and then walked to where the victim was sitting.
He then "calmly poured the bucket of water over the back of the complainant's head, neck and shoulders", the summary reads.
The victim jumped from his seat while Show shouted at him. The victim ran from the cafeteria, down the stairs and into the first aid room.
A kitchen worker then confronted Show and struck him in the head with the plastic bucket.
Show then calmly turned, walked back to his table, sat down and continued to eat his food.
The victim suffered second-degree burns to about 15 per cent of his body.
A spokeswoman for Turners and Growers said the company was pleased the matter had been settled through the courts.
"Our focus has been on our staff member and supporting him through recovery and getting him back to work," she said.
Show's lawyer, Leo Lafferty, said it "would not be proper" to comment about the case following the court's decision because his client was now in custody and he would need to receive instruction from him before saying anything.