What is the proper procedure for reheating previously cooked TCS food?

Reheating of previously cooked TCS food for hot-holding: must reach 165°F (74°C) for 15 seconds within 2 hours, throughout the food. Critical points: (1) TIME LIMIT — reheating must occur quickly to minimize time in temperature danger zone; 2 hours maximum from start to reaching 165°F; (2) EQUIPMENT — use stovetop, oven, microwave, or other equipment capable of rapid heating; steam tables, warmers, hot-holding equipment are NOT designed for reheating — they maintain temperature but cannot reheat efficiently; (3) MEASUREMENT — use calibrated thermometer; check multiple locations including the coldest spot (typically the center or thickest part); ensure entire food has reached 165°F; (4) MICROWAVE PROCEDURE — cover food; rotate or stir during cooking; let stand 2 minutes after heating to equalize temperature; check temperature in multiple locations after standing; (5) DOCUMENT — record reheating temperatures, especially for HACCP plans or operations with prior issues; (6) SPECIAL CASES — Roasts: per Food Code, large roasts may be reheated to different temperatures depending on size and method (135°F internal acceptable for some commercially processed items in unopened packaging); Pre-cooked commercial items in original sealed package designed for warming may be brought to 135°F (not previously opened, not cooked on premises); (7) COOLED THEN REHEATED — food properly cooled and stored at ≤41°F can be reheated once; after reheating, must be either consumed immediately, hot-held at 135°F+, or discarded; cannot re-cool and re-reheat repeatedly; (8) REHEATING IS NOT THE SAME AS INITIAL COOKING — initial cooking has different temperature requirements for different foods (poultry 165°F, ground meat 155°F, intact meat 145°F, seafood 145°F); reheating always to 165°F regardless of food type. Why 165°F: rapid pathogen reduction; some pathogens (especially Clostridium perfringens, Bacillus cereus) can produce heat-stable toxins if cooling was inadequate, and reheating destroys spores but not toxins — proper cooling remains essential.