(Advance warning to all non-Americans: I only know how to relate this information in Fahrenheit.)
The current temperature danger zone is 41º - 135ºF. Any foods within those extremes must be given extra attention. Basically, it means to refrigerate at 41º and below, and to hold hot food at 135º and above.
Techie Smurf brined his turkey this year in a big stockpot. The pot didn't fit in the fridge. Fortunately, it was very cold outside in Indiana. We left it on the porch all night, which was considerably colder than the inside of the fridge. The next day did get above 41º, so someone had to check the pot every couple of hours to make sure the ice hadn't melted.
The heating requirement does not mean that you can cook anything to 135º and call it done. There are all sorts of charts about what kinds of meats must be cooked to what temperature. The two biggies, Salmonella and E. coli, are eradicated at 165º. When it doubt, cook to that temperature. But the 185º that most cookbooks tell you to cook a turkey? If you do that, once it stands, it will be more like 200º, and dry as jerky. You can pull poultry and meatloaf at 160º, and they will easily be done after standing a few minutes.
Which brings up ground beef, or ground any meat. The grinding process exposes more surfaces of the meat to potential pathogens, mainly E. coli. Plus, it's a lot harder to sanitize a grinder than a single blade. Cook that as thoroughly as you would poultry, just in case.
Eggs cook around 135º. Before you freak out about Salmonella, be assured that most eggs in the American food supply do not carry it. If you're making something that might have raw or undercooked egg in it, you can buy pasteurized eggs. They taste about right, and knowing that your Hollandaise won't kill your guests makes it taste better.
When cooling something that has been cooked, time is the key. You have a total of four hours that it may be in the danger zone. So, if you had Thanksgiving dinner in an hour, then put away leftovers and they chilled to 41º in another hour, you have already used up two hours. If you make a leftover turkey sandwich for lunch and pack it in a non-insulated lunch bag, I hope you plan to eat fairly soon after making the sandwich.
This is also industry-standard for food handling places. Obviously, four hours and one minute will not make you sick. Five probably won't, either. Mainly, be conscious of any time or temperature abuse that leftovers may have suffered. Reheating them to 165º resets the clock, which is basically the concept behind frozen TV dinners.