The snow had just stopped falling but the wind was whipping at 20 mph off the hybrid grass/artificial turf playing surface. It was 30 degrees, but it felt 17 with the wind chill, and the Raiders had taken the field for pregame warmups in Philadelphia.
It was the Raiders' lone cold-weather game of the 2025 season and they came prepared. Players from punter AJ Cole to quarterback Kenny Pickett to running back Ashton Jeanty to receiver Jack Bech to linebackers Devin White and Elandon Roberts to cornerbacks Eric Stokes and Darien Porter were all wearing a familiar, fanny pack-looking piece of tear-away equipment around their waists.
The so-called Muff hand warmer.
Yes, the creation of Raiders owner Mark Davis, who came up with the idea of combining existing fleece-lined hand warmers with heat packs in 1986. An "invention" that is now a standard piece of NFL equipment to deal with the elements.
Oh, you didn't know Davis was its designer and marketer? Take a trip with us, then, on the lore of The Muff.
The Muff's origins began on Oct. 3, 1983, a balmy 68-degree day in the nation's capital. Cliff Branch had hauled in an NFL record-that-will-never-be-broken 99-yard touchdown pass from Jim Plunkett but at about the Washington 30-yard line, his right hamstring yanked on him. Branch would miss four of the Raiders' next five games.
Looking for a way to rehab, Branch, with the help of Davis, who had once served as his agent, sought out Far East remedies. A friend of Davis' recommended "homeopathic" treatment in Los Angeles' Little Tokyo.
"There was a product called Kyolic, and it was a garlic extract, and it had to do with either thinning the blood or getting the blood circulation going better," Davis said.
Branch, who was also undergoing acupuncture treatment, started a regimen and "got better really quickly," Davis said.
Davis, who was also working as a scout for the Raiders at the time, was so impressed with the product he hoped for a meeting with the company to set up a distributorship.
"So when I went over to Japan for the Japan Bowl, I met with the company up in Oketo and they took me up to their factory where they make all the stuff and they looked at me, and they said, 'You know, we've got all kinds of products and things that you might be interested in,'" Davis said. "And one of the products he showed me were those heat packs."
The disposable, single-use hand-sized heat packs activated by shaking them and exposing them to air were not yet quite a thing in the U.S.
"As a water boy, we are always looking for ways to keep our hands warm," Davis said.
Gloves were thick but got wet. The little encased coal burners that fit in pockets would often times burn the users. In the 1960s, teams would sometimes light coal on fire in buckets on the sidelines to gather around for heat.
"You'd find a lot of old jerseys that were burned or melted because the guys were so close to them," Davis laughed. "So when I went up to the factory for the garlic, they showed me these heat packs that are exothermic principle, you just shake them. They were sand and iron inside and they would create heat and they'd stay hot for 24 hours. And I said, 'Holy sh--, this is something.'"
Davis worked out a distributorship deal and brought the packs to equipment managers shows and athletic trainers shows. Oklahoma trainer Dorman Knight was impressed…with a caveat.
"Can you come up with something so we don't have to sew pockets on all the jerseys?" Knight asked Davis. "Because it's really tough to bring two sets of jerseys to all the games and travel for everybody. And could you come up with something that's portable to put these heat packs in?"
Davis, who had majored in economics and minored in history at Chico State, went to work. In a familiar place.
Remember when the Raiders wore silver capes on the sidelines for warmth?
"They had a polar fleece interior," Davis said. "And in doing some experimentation, I found that the polar fleece really made the heat packs heat up even better, and maintained them at a high temperature.
"The capes were a great vehicle to make a muff out of."
Davis asked the cape's creator to make some prototypes, using the fleece with a pocket in which to place the heat packs on the inside and nylon on an existing hand warmer.
"We realized one layer of fleece didn't work," Davis said. "It had to be two layers of fleece for the air to circulate. And this was very rudimentary science that we were doing, but it was through, you know, trial and error to figure out that one piece really wasn't doing it because it would get moisture in the inside of the nylon.
"The two pieces of fleece actually did it. So we put one piece of fleece inside and then the piece that had the cuffs was a bigger piece that would be on the outside. So that would be the second piece."
A tearaway belt was added. The end product?
"They worked spectacularly," Davis said.
Next? Licensing.
"We went out and got licenses for the NFL, Major League Baseball," he said. "We got the license for hockey. We got the licence for a lot of the colleges, to put their logos on it."
But he did not patent it.
"Because it really was two products going together as one - muffs had been around forever so it would just have been the components that we were using," Davis said. "But by licensing it, we had control over the market, so to speak."
When he approached NFL teams, "a lot of them scoffed at it," Davis recalled.
But not the Buffalo Bills, who played in notoriously bitter weather in winter home games. Jim Kelly, who would become a Hall of Fame quarterback, was one of the first to appreciate it.
"Jim was really the champion of this product," said Davis, who became business partners with Kelly. "As far as he was a promoter of the product, and so we've known each other for all that time. Then, of course, everybody else just started wearing it and it became a standard piece of equipment in the National Football League and that was kind of cool to be, you know, a water boy and coming up and trying to do something and actually coming up with a piece of equipment that now permeates the sport."
A game-worn and signed Kelly hand warmer from the 1990-91 season recently sold for $2,040.00 on Heritage Auctions.
It all could have made for an awkward moment, or three - the perception that the son of the Raiders owner was helping Raiders opponents.
In December 1988, two days after the Seahawks, then in the AFC West, beat the Raiders in the season finale to win the division and advance to a playoff game at frozen Cincinnati, the younger Davis' hand warmers arrived in Seattle.
"Just stay toasty, baby," John Clayton wrote for McClatchy News Services at the time.
In January 1991, days before the Raiders played at Buffalo in the AFC title game, the younger Davis met with Kelly to discuss merchandising plans for The Muff.
And Al Davis was asked (facetiously?) by Doug Krikorian of Knight-Ridder Newspapers, "What do you think of your son consorting with the enemy?"
Davis' response? "Please, don't bother me with such stuff."
Said the younger Davis at the time: "The way I see it, The Muff will help both sides equally. Sure, Jim Kelly will be wearing it, but so will Jay Schroeder. [Bills receiver] James Lofton will be wearing it, but so will [Raiders receiver] Tim Brown. I don't see where either team will have an advantage."
The Bo Jackson-less Raiders fell, 51-3.
Still, Brown was the most high-profile Raider to wear The Muff in his tenure, be it in L.A. or Oakland. Be it in cold-weather roadies, or in sunny California home games.
"People would say, 'Well why do the Raiders need it?'" Davis said. "Well, because we travel."
Brown called The Muff a "cheat code" for him in his Hall of Fame career. Since he never, if rarely, wore gloves (he only taped his fingers after dislocating the middle digits as a rookie in 1988), the hand warmer provided something else, besides warmth.
Rhymes with Hickum. Kinda.
"It would get wet and your hands would almost get sticky," Brown said on the NFL Players: Second Acts podcast. "But that's between us, right?
"I never had an issue again."
Davis said the device was meant to be "utilitarian," with several versions for players, which was just a strict tube, while a fan version had zippers on both sides and a pocket on the front or pack to keep personal objects things in.
"Now," Davis said, "there's other people making them, obviously."
In all, the Raiders took between 30 to 40 Muff-inspired hand warmers to Lincoln Financial Field, said director of equipment operations Bob Romanski.
"All the wide receivers and DBs, we just leave them at their lockers and they kind of just do it themselves," said Romanski, who has worked in the Raiders equipment room since the early 1970s and has seen the evolution of the hand warmer up close and personal.
From containers that "looked like fancy ashtrays" with felt on the outside but were filled with burning charcoal sticks after being lit by mini-torches, to sewing pockets on the fronts of jerseys.
"But that just gave defenders something else to grab onto to tackle them," Romanski said.
Pickett, meanwhile, said he had been using hand warmers since, well, "forever. Since I was 11 or 12. Since Pop Warner.
"It's helped a lot of players throughout the years so I know we're all thankful for it. … It's full circle finding out that [Davis] made them. I've been using them my whole life, so that's pretty cool."
Nary a soul in the Raiders locker room had any idea on the Raiders owner's role in developing a mainstay piece of football equipment.
Cole said his "mind is blown," while adding he would thank Davis personally after keeping his hands warm in frigid Philadelphia.
Davis smiled.
"I am [proud]," he said. "Yeah, that was a good five-year product. Again, when it got away from entrepreneurship and it's actually running a business, it wasn't as much fun. It was more fun being on the creative side, and doing it. But it was a very, very good learning experience for me in learning the ways of the National Football League, learning ways of the licensing thing. Because back in the '90s, when this was coming out, licensing was just really starting off."
Which led to Davis' creation of the Raider Image apparel stores.
From Branch's Hall of Fame hamstring pull to Japanese supplements to heat packs to Raiders capes to The Muff to the Raider Image.
"It's just another piece," Davis said. "Another piece of my evolution."
Illustrations by Harrison Freeman.
