Kindly mention age and weight of baby. It can be because of viral infection. Is there any other symptoms like burning micturition, fever with chills, any rash.
Keep your child hydrated, give her ORS, lemon water if she is more than 6 months old, give her fever medicine according to weight, watchful for dehydration, lethargy.
Watch these video on my YouTube channel ( Gagahealth ) for home care during fever and diarrhoea.
https://www.youtube.com/watch?v=AdFB0s6Or3c&list=PLMHyMmrLfhIUwQq0GdUK9KNqM2M9lQURW&index=1
https://www.youtube.com/watch?v=i9yDKEbmo80&list=PLMHyMmrLfhIUwQq0GdUK9KNqM2M9lQURW&index=2
Next Steps
Consult to your paediatrician if fever persist.