The search for retired Air Force General William Neil McCasland, who has gone missing, is being hampered by unusually warm spring temperatures in New Mexico, authorities have reported.

The expansive search area and the heat in Albuquerque are complicating efforts to use thermal drones in the investigation into McCasland’s disappearance, according to a statement from the sheriff’s office during a press conference on Monday.

McCasland, 68, was last seen at 11:10 a.m. on February 27 by his wife, Susan. She returned home from a medical appointment less than an hour later to discover that her husband was nowhere to be found, as detailed by the Bernalillo County Sheriff’s Office.

Lieutenant Kyle Woods explained to reporters, “Unfortunately, we’re experiencing one of the warmest springs in years. The thermal imagery from the mountain is so intense, it’s as if it’s lit up like a candle, even at night.”

Woods added that this situation makes it difficult to distinguish between heat signatures from people and the natural heat emitted by the rocks.

Authorities have issued a Silver Alert for the retired general, who is also a known UFO expert. The alert was prompted by McCasland’s previous reports of experiencing a “mental fog,” which led him to step down from various roles. However, investigators noted that they believe McCasland was mentally sound at the time of his disappearance.

“There’s no indication, and we are not putting forward that Mr. McCasland was disoriented or confused,” Woods said.

“Arguably, he would still be the most intelligent person in the room that any of us would be in. Highly intelligent, highly capable, but that information was given to us early on, and out of an abundance of caution, we escalated to a Silver alert to try to garner as much public attention as possible to try to help locate him as soon as possible,” he continued.

Investigators said his wallet, a .38 caliber revolver with a leather holster and a red backpack are still unaccounted for and missing from his home. Nearby residents are still being asked to hand over any possible surveillance footage to assist with the search.

It was uncommon for the UFO expert to leave his home for a hike without his phone or wearable devices, though both were found in his home.

McCasland might have vanished in a green shirt and hiking boots, but the items were later located at his second home in Pagosa Springs.

A gray US Air Force sweatshirt was also discovered 1.25 miles east of McCasland’s home on March 7, though his family was unable to confirm whether it belonged to him. The discovery of the clothing item led to additional searches in the nearby area, authorities said.

Local authorities, working alongside the FBI, said they’ve received dozens of tips in the missing persons case — although none have yet to bear any fruit.

During his military career, McCasland headed up research at Wright Patterson Air Force Base — a role in which he oversaw classified space weapons programs.

The base, near Dayton, Ohio, is rumored to own extraterrestrial debris allegedly from UFO hotspot Roswell, New Mexico.

He was also a longtime leader at the Kirtland Air Force Base in New Mexico and had prior stints at the Pentagon before retiring in 2013.

His wife has since downplayed the UFO community ties as she sought to clear up so-called “misinformation” about her husband’s disappearance.

“Neil does not have any special knowledge about the ET bodies and debris from the Roswell crash stored at Wright-Patt,” she wrote on Facebook on March 6.

Investigators are still combing through video evidence and investigative tips and have had no confirmed sightings of McCasland thus far. The all-out search for the seasoned outdoorsman has included drones, helicopters, and dogs, police said.

“There are some tips with some outlandish theories, conspiracy theories, we will look into everything,” Sheriff Josh Allen told reporters.

“But we are trying as a law enforcement agency and entity to look into facts to make sure that we can retrace before Mr. McCasland went missing and to also make sure we are looking into any clues for anything that was nefarious,” Allen said.