What should the temperature of an 18 month old be?

For an 18-month-old child, a normal body temperature typically ranges from about 97°F (36.1°C) to 100.4°F (38°C) when measured orally. A fever is generally considered to be a temperature of 100.4°F (38°C) or higher. It's important to monitor other symptoms and consult a healthcare professional if the child exhibits signs of illness or if the fever persists.