NATICK, Mass. (May 30, 2013) -- If you're familiar with the phrase "rock or something," then you've probably used a Flameless Ration Heater to warm up a Meal, Ready-to-Eat.To this day, the phrase remains part of a pictogram on the package of the heater, known as the FRH, which was developed at Natick Soldier Research, Development and Engineering Center's Department of Defense Combat Feeding Directorate and is celebrating its 20th anniversary in 2013. It refers to directions that advise warfighters to place the FRH at an angle when heating up a Meal, Ready-to-Eat, commonly known as an MRE."The term 'rock or something' has now reached cult status," said Lauren Oleksyk, team leader of the Food Processing, Engineering and Technology Team at Combat Feeding. "It's just taken on a life of its own."Oleksyk was there at the beginning with colleagues Bob Trottier and now-retired Don Pickard when the FRH and that memorable phrase were born in 1993."We were designing the FRH directions and wanted to show an object to rest the heater on," Oleksyk recalled. "(Don) said, 'I don't know. Let's make it a rock or something. So we wrote 'rock or something' on the object, kind of as a joke."The joke has legs. As Oleksyk pointed out, there now are T-shirts and other items for sale that bear those words. "Rock or something" even has its own Facebook page.Introduced to the heater years ago, famed chef Julia Child insisted on following the package directions and activating it by herself. With no rock handy, she decided to employ a wine glass stem."Which is so classic Julia," Oleksyk said, laughing. "So there have been many things other than the rock or something that have been used. There are many, many Soldiers over the years that have their own personal joke about what they might use in place of a rock."The FRH is no joke, however. Adding an ounce and a half of water to the magnesium-iron alloy and sodium in the heater will raise the temperature of an eight-ounce MRE entrée by 100 degrees in about 10 minutes."Some of the challenges were keeping it lightweight and low volume, and not requiring a lot to activate it," Oleksyk said.The heater's arrival gave warfighters the option of a hot meal wherever they went and whenever they wanted."I've heard more feedback on this item than any other item I've ever worked on in my career here," said Oleksyk, who has been at Natick nearly 30 years. "They're so grateful to have this heater in the MRE. It's almost always used whenever they have 10 minutes to sit down for lunch."Prior to the FRH, warfighters used Trioxane fuel bars with canteen cups and cup stands to heat their MRE entrees. As Oleksyk pointed out, the fuel bars couldn't be packed alongside food in the MRE package."So if the fuel bar and the MRE didn't marry up in the field," said Oleksyk, "they really had no way to have a hot meal."The FRH has remained essentially the same over the past two decades because, as Oleksyk put it, "it's tough to find a better chemistry that's lighter in weight, lower in volume and that heats as well." A larger version has been developed, however."We've expanded it to a group ration," Oleksyk said. "So now we have a larger heater that is used to heat the Unitized Group Ration-Express. We call that ration a 'kitchen in a carton.' It serves 18 Soldiers."The next-generation MRE heater is being tested now, and it will eliminate the need to use one of the most precious commodities in the field."The next version of this is a waterless version," Oleksyk said. "It's an air-activated heater, so you wouldn't have to add any water to activate it at all, but that's still in development and will have to perform better than the FRH overall if it's ever to replace it."Oleksyk remembered sitting on a mountain summit one time during a weekend hike with friends. Suddenly, she heard laughter behind her."I hear a guy -- sure enough, he says, 'Yeah, I need a rock or something,'" said Oleksyk, who turned to see him wearing fatigues, holding a Flameless Ration Heater, and telling his buddies how great it was."So it's far reaching," Oleksyk said. "It really had an impact on the warfighter."