BATON ROUGE (AP) — A federal judge has ordered temperature data be collected for 21 straight days in advance of an Aug. 5 trial of a lawsuit by three condemned killers who claim extreme heat indexes at the Louisiana State Penitentiary at Angola amount to cruel and unusual punishment.

The Advocate reported the suit, filed last month, alleges heat indexes on death row at the prison reached 172 degrees Fahrenheit last year and 195 degrees in 2011. . The suit contends the heat index on all six death-row tiers was above 103 degrees every day last August, and that inmates on one tier endured heat indexes of more than 126 degrees “on 85 days between May and August.”

Chief U.S. District Judge Brian Jackson’s order Tuesday came at the conclusion of a court hearing during which an attorney for the state Department of Public Safety and Corrections and the prison called the inmates’ data “greatly exaggerated,” ”faulty” and “generally incompetent.”

A lawyer representing death-row inmates Elzie Ball, James Magee and Nathaniel Code countered that the men, each of whom suffers from hypertension, face the very real possibility of heat-related illness — including heat stroke, paralysis and heart disease — and even death.

The suit asked Jackson to issue an order compelling prison officials to maintain a heat index on death row of no more than 88 degrees.

“The court will not grant the injunction today. That is the fair and appropriate thing to do,” the judge told both sides Tuesday while noting that even death-row inmates are entitled to constitutional protections. He said more evidence on the suit’s claims needs to be gathered.

Jackson ordered the two sides to meet and file a joint plan by July 9 concerning what evidence will be collected and shared. If a plan is submitted, the judge said, he will approve it July 10. Otherwise, Jackson said he will issue his own plan on that date.