As long as the food was cooked properly the first time and proper storage precautions were observed, then there is no set temperature that must be reached in order to safely reheat it. Warm to whichever temperature you desire in order to enjoy it.
145-155
165
In the US, the Food and Drug Administration department recommends a minimum temperature of 135 º F (57 º C). The danger zone is 41º F - 135º F. Potentially hazardous foods exposed to this temperature range for a cumulative total of more than 4 hours are not safe to eat. Pasta and rice dishes should be cooled to below 41ºF as quickly as possible to prevent the growth of Bacillus cereus that can produce a toxin, especially in foods that are cooled slowly. Because this toxin is heat-resistant, it's not destroyed by reheating to any temperature.
Food should be hot held at 135 F for no more than 4 hours. Food should be reheated to 165 F for at least 15 seconds before the 4 hour point is reached.
Potentially hazardous food should not be left out for more than 2 hours, after which time it should be either refrigerated or reheated. If the ambient temperature is very warm, cut that to 1 hour.
Reheated food can be eaten hot or cold. This is assuming that the reheated food isn't older than a few days.
75 Degree's C or higher
Most shellfish should not be reheated, as the threat of botulism is high for them.
Foods such as meat must be heated to at least 180 degrees in most cases. It depends on what the ingredients are. Chicken should be reheated to 180 degrees. Turkey should be heated to a temperature of 185 to 190 degrees. Beef that has been precooked can be eaten cold if it was refrigerated after cooking as is with chicken and turkey. Pork should be heated to 180 degrees.
Raw poultry should not sit out any longer than it takes to prep it for cooking.
You should keep hot foods hot and cold foods cold. The temperature to keep bacteria out of hot foods is 160 degrees and above. Cold foods should be kept at 40 degrees or below.
It should not be left out for more than 2 hours. At that time, it should be reheated or refrigerated. Less time is better.