Since we might only see the child for a few minutes, it is important to take seriously any significant events that have occurred recently. Pale, floppy or blue episodes are all notable. Shivering and shaking are also worth taking into account. They are not in themselves proof of serious infection. Any of these things can occur during a temperature spike in an uncomplicated viral illness. Remember that each of these is only a piece of a jigsaw. You need to look at the whole picture and if the child is now running around pretending to be Spiderman, they’re probably OK despite the thing that happened.
A well-hydrated child (wet mucosa etc) who is drinking well and has good urine output is what you are looking for here. Where these things are not adequate, sometimes all that is required is analgesia and a fresh start. It all depends on how the rest of the pieces of the jigsaw are coming together as to whether it is time to go down a particular path. Dehydration and poor urine output combined with other features is more significant.