The units will be installed across Roebourne Regional Prison in the 2023-24 financial year and cost more than $10 million, Corrective Services Minister Bill Johnston says.
Concerns about the extreme heat at the Pilbara facility have been raised for years, with a custodial inspector in 2020 expressing grave concern at the lack of climate control across the mainstream prisoner accommodation.
In response, the state government listed ice machines among the existing "effective controls" and claimed prisoners from the region were used to the heat.
The temperature in Roebourne exceeded 50C earlier this year, with the Aboriginal Legal Service of WA labelling the treatment of prisoners as inhumane.
Mr Johnston said the government had listened to community concerns about the potential effects on the health and safety of prisioners.
"This is a significant investment by the state government towards prisoner welfare at Roebourne Regional Prison," he said in a statement on Wednesday.
"This project will factor in the local climatic conditions and challenges posed by installing air-conditioning in a humid tropical environment.
"Ahead of this work being completed, the prison's management will continue to be vigilant in safeguarding prisoners' wellbeing through existing practices."
Mr Johnston said the facility had air-conditioning in some common-use areas and cells designated for prisoners with medical conditions and those who had been doing outdoor work.
Most prisoners rely on fans to cool their cells during the summer.
Premier Mark McGowan on Wednesday hosted a meeting to discuss issues at the Banksia Hill youth prison, including the use of dangerous restraint techniques.
The government has directed staff to stop using the "folding-up" technique, which involves officers using their body weight to force a person's arms and legs against their head.
Judges, lawyers and advocates have also raised concerns over repeated lockdowns at Banksia and the decision to transfer a small group of teenagers to a standalone unit at the maximum-security Casuarina adult prison.
Mr McGowan told parliament the meeting with stakeholders had been positive and further changes would be announced in coming weeks.
The state government has been forced to delay a number of projects during the COVID-19 pandemic, mostly due to labour and material shortages.
An on-country youth rehabilitation facility in the Kimberley will open in the second half of 2023, six months later than initially planned.
It will provide up to 16 places each year for teenage boys aged 14 to 17 as an alternative to Banksia Hill, the government announced this week.
18°C