Reheating shrimp is safe, provided that the leftovers are reheated to a temperature of at least 165 degrees Fahrenheit. A food thermometer can confirm the internal temperature of the shrimp, and reheating to 165 degrees kills potential pathogens, including vibrio, which is commonly found in undercooked shellfish.
Raw shrimp should be refrigerated at temperatures of 40 degrees Fahrenheit or lower within two hours after purchase. Raw shrimp should also be cooked within two days of purchase and should be heated until the flesh is pearly and opaque. Leftover shrimp should be refrigerated within two hours of cooking and eaten within three days of the initial preparation date.