Mayor Bill de Blasio told New Yorkers that the heat index over the weekend could reach 110 degrees.

“We’ve got a really challenging next few days coming and this kind of heat can be dangerous,” de Blasio said Friday on WNYC.

“In terms of the heat index, we’re talking later today, Saturday, Sunday well over 100 in each case, meaning it’s going to feel over 100 degrees, could be over 110 degrees,” Hizzoner said.

“Don’t go outside if you don’t need to. Don’t go in the sun if you don’t need to,” the mayor said.

“If you feel faint, if you feel nauseous, if you have an intense heartbeat, that could be heatstroke. Call 911. Get help immediately,” he said.

De Blasio asked New Yorkers to set their air conditioners to 78 degrees to conserve power. Thursday he ordered tall buildings to raise their thermostats to 78.

The mayor reminded listeners that beaches will be open from 10 a.m. to 7 p.m. and pools from 11 a.m. to 8 p.m. Friday through Sunday. There will also be 500 cooling centers available to the public.

De Blasio promised to keep a close eye on Con Edison following last weekend’s blackout.

“We’ll be talking to ConEd, pushing them, monitoring them literally hourly to make sure we get through this,” the mayor vowed.

On WNYC, the mayor received a call from a Crown Heights resident who said the elevators in his Pacific Street building had been out for two months and the landlord claimed a city Buildings Department inspector was responsible for delaying the repairs. The mayor said he’d speak to the commissioner of the department today and get the problem fixed immediately.

De Blasio also took heat from WNYC host Brian Lehrer, who peppered Hizzoner with repeated questions about the potential firing of Police Officer Daniel Pantaleo.

The mayor refused to say whether he would ax Pantaleo over the death of Eric Garner in 2014.

“I’m not going to get into hypotheticals,” de Blasio said, adding, “There’s been a trial and there will be a final decision in August.”