Corrections has spent over $305,000 on slushy syrup and maintaining frozen ice machines in the past six years.
The news comes as proposed job cuts ravage the public service with 3460 jobs set for the chopping block, as part of the cost savings drive.
The slushy machines caused controversy in 2019 when it was revealed Corrections had spent over $1 million of taxpayer money on 193 slushy machines.
The then-National leader Simon Bridges called it "irresponsible and wasteful spending" at the time but then-Corrections minister Kelvin Davis said was about health and safety.
Since then the slushy fund has continued with 160 of the 193 original machines still in use and $305,906 spent on syrup, maintaining them.
The figures were released as part of a request under the Official Information Act to a member of the public.
It showed that over the past six years, Corrections spent a total of $217,273 on slushy machine syrup. That figure includes some maintenance.
A further $81,598 was spent on maintaining and cleaning the machines and $7035 was spent on "other consumables".
In a letter accompanying the data, Corrections' commissioner of custodial services Leigh Marsh said the organisation had a duty that included minimising "the risk of heat stress" to prison staff.
"In the summer months frontline staff work tirelessly to manage prisoners in hot and confined spaces and conditions, sometimes while wearing heavy equipment such as stab resistant vests.
"The heat, combined with the increasing number of prisoners, has the potential for significantly increased prisoner tension and aggression, and the real risk that a staff member or prisoner could be seriously hurt."
He said the machines were introduced, for staff only, following the summer of 2017/18 when the country experienced a hot dry summer, with Wellington recording its hottest January since records began in 1927.
"Research shows that crushed ice drinks offer an immediate and effective means of significantly reducing core body temperature in most situations, up to three times more effective when compared to drinking water."
When asked what research the department was relying on, a spokesman pointed to an article in an academic journal titled "Crushed ice ingestion - a practical strategy for lowering body temperature".
Like other government organisations, Corrections has been asked to make spending cuts.
Corrections has a target of reducing spending by 6.5 percent.
Deputy chief executive of strategy and corporate services, Alice Sciascia said Corrections has paused the recruitment of "back-office staff" that are not essential.
- This story was first published by Stuff