Newswise — MANHATTAN, Kan. — The recall of 1.8 million pounds of beef for possible E. coli contamination may now be extended to grocery stores. A Kansas State University food safety specialist warns consumers to be extra careful when grilling out this holiday weekend.

Bryan Severns, director of food programming and services for Kansas State University Olathe, says all food, especially raw meat, has pathogens in it.

"You want to make sure that you’re not ingesting live bacteria when you eat your hamburger because it has a tendency to have E. coli, salmonella and listeria in it," Severns said.

The way to kill those bacteria is to cook hamburgers to 160 degrees Fahrenheit, while hot dogs should be cooked to 165 degrees Fahrenheit. And Severns says to be sure you are using the right type of thermometer. A dial thermometer has a dimple about three quarters from the tip and is used to measure thick cuts of meat. An ideal thermometer for hamburgers and chicken breast is a digital thermometer, which picks up temperature at the tip of the device.

"It is vital to check the temperature of the meat because the color of the meat does not tell you if it’s done," Severns said. "If you happen to have some old hamburger in the refrigerator for awhile, it might be oxidized and start off raw but brown all the way through."

Also be sure you are using separate utensil for raw meat and cooked meat and don’t leave food sitting out for more than two hours. Check this chart, http://www.foodsafety.gov/keep/charts/mintemp.html, for other important cooking temperatures.