Do I need to take his rectal temperature? Should I give him acetaminophen or is rest enough?

Question

My boy had his 12 month shot this morning. He fell asleep in my arms and I thought he was very warm, so I took his temperature under my arm and I get 38.8C. In his mouth, I got to 39.4C. Thank you!

Charles Dignard · Accepted Answer

Hello, Since this is a normal side effect after vaccines (immune system reacting), I don't see the absolute necessity to take your child's rectal temperature, although it is the most reliable value. On the other hand, I am not overly concerned about the values obtained under the arm and in the mouth. However, I would suggest that if your child is still warm, you should take the next measurement in the rectal area. Dress him in light clothing and give him acetaminophen according to his weight if you find he seems affected. If the values are over 40, if the fever lasts more than 72 hours or if he develops other symptoms that worry you, I advise you to go see your regular pharmacist if possible. Hope this helps, Charles