My granddaughter has a temp of 102.3 she doesn't have any other symptoms. what temp warrants a visit to the er?

High fever: If you can control the fever with antipyretics, bathing in luke warm water & keep the child hydrated no need to go to ER. But if it persisted, temp of 103 & above especially if there are other symptoms like Convulsion, vomiting, lethargy, earache, cough, refusing to eat or drink, rashes. It is best to call her pediatrician he will give you the best advice to go see him or go to ER