@Ildiko, I too ended up in hospital after the Docetaxel.
I had FEC before, with no problems but low neutrifils, so had the Neulasta injection after each one, but with the Docetaxel, even though I had the Neulasta the day after chemo, by day 4, my temperature started to climb.
I was hospitalised on IV antibiotics after the first two Docetaxel chemos, with every scan and test under the sun, nothing showed up except extra lung nodules.
For the last dose my Oncologist prescribed oral antibiotics to start taking on day 4, my temp started to rise a little that night, and again on the night after, both times reduced with Panadol, then I had no more problems with high temps.
I have spoken to others who have said the same thing.
Perhaps it is a reaction to the chemo drug rather than an infection, as in my case no infection was found anywhere, but they kept up the antibiotics just in case.
It seemed too much of a coincidence that it always started on day 4 evening.