Record hot temperatures have sparked a call for air conditioners to be installed at one of the country's largest prisons.
Prisoner rights group Howard League for Penal Reform has received a number of calls about extreme temperatures in container cells at Rimutaka Prison in Upper Hutt.
Department of Corrections acting national commissioner Jeanette Burns told Newshub the prison is giving those affected iced water and hand-held fans, as well as more out-of-cell activities.
"In addition, we are providing sunscreen lotion, prisoners have access to fresh running water in their cells, and there is no restriction on the number of showers they are able to take when unlocked."
But the group says that is not enough and is demanding that air-conditioners be installed in the cells.
"The cells are very small for two men and only have little holes in them to get air in," Howard League spokesperson Madeleine Rose says.
"We also understand that they are going to bring in more staff so that the prisoners in these cells can have longer unlock hours. This has not happened as yet."
The group claims prisoners are "passing out" in the heat, but Corrections says there is no evidence to back this up.
"An ambulance was called for a prisoner in the unit recently, however his medical issue was unrelated to heat," the Corrections spokesperson said.
"We are aware of the effect of the temperatures on our facilities, and we are taking proactive steps to prevent potential harm to prisoners."
January has the hottest month in recorded history. NIWA says the heat is set to continue over the coming weeks.