If your 2-month-old baby has recently received their first vaccinations and is experiencing a fever, it is important to monitor their temperature. If their rectal temperature does not exceed 38 degrees Celsius, there is generally no cause for concern. However, if the fever persists for 2 days or more, it is advisable to seek medical advice. In the meantime, you can give them fever-reducing medication like Tempra and encourage them to stay hydrated by drinking plenty of fluids. If you have any further questions or concerns, do not hesitate to reach out to a healthcare professional for guidance.