garfield,
Yes, Soph had it once like that.
She had fever on a Tue and Wed (no more than 38.5), then by Thur OK, so PD gave go-ahead to go Malacca for the weekend.
When we came back the following week, she got fever again on a Tue, and went up to high of 39 on Thu and 40 on Sat night.
Thu: Went to PD, Did a swab test to see if it's common cold virus... it's not. So PD says fever come and go, probably some infection somewhere, and gave antibiotics Klacid.
Sat night: When fever reached high of 40 even with antibiotics, we took her to A&E. Did a blood test, shows high white blood cell count, so definitely some infection somewhere (likely throat). Doc switched antibiotics to Augmentin (with PD's approval cos I called up PD) and her fever went down from there. But PD says it's not totally AUgmentin's credit, but cos Klacid normally takes about 2 days to work, so even if we stuck with Klacid, her fever could have come down if we waited a bit longer.
She still had fever on Sun and slightly on Mon, but the highs are never as high as 40... i.e. the "highs" should get lower in the recovering stage.