The doctor was there in the night, gave Amy a cursory checkup and said it looked to him like a viral infection. He prescribed some homœopathical drops against that and told me where the nearest chemist's on night duty was—a fair distance away in Kirchdorf. (The only one in Harburg that was on night duty last night was only open until 10 p.m.)
I called Thomas and he kindly agreed to drive me there; I suppose he knows what it's like to worry about little children, having two of his own. It took a while for the chemist to arrive, and I was worrying whether the doctor had given me information for the wrong day or whether the bell was working (since somebody had melted the plastic with a lighter a bit); turned out he had probably been sleeping, judging by his general composure. He filled the prescription and we went home. Stella gave Amy the drops and also some more ibupofen syrup to try to bring the fever down.
This morning, Stella says that Amy's temperature seems to be back to normal again: while last night, her limbs had been cold and her torso and head hot, this morning her feet were warm and her head was cooler again. So maybe we're over the worst.
Thank you all for your words of concern on my previous entries.
Edit: 36.7 °C (98.1 °F) this morning.