Ever notice why we usually notice our fever when its in the afternoon? I always thought that it was because we were tired from the whole day but it's not just that. The natural cycle of our internal thermostat explains why doctors get most of their phone calls about fever in the late afternoon and early evening. Apparently, everyone's temperature rises in the late afternoon and early evening and falls between midnight and early morning.
So don't be alarmed when baby's temperature rises a bit in the afternoons and early evenings but it doesn't mean that if their temperature is up at that time that you shouldn't worry. A fever is still a fever.