Hello dear and thanks for the query
The only chance that the temp is due to fall is if there is any kind of hematoma
at the site of injury whether it is external or internal. Else it is coincident. As you have explained rectal temp is 100.6 so the body temperature is 99.6 which is not very high and can be due to warm weather. Get a axillary or mouth temperature to sure that your daughter has temp. Continue with tylenol
and if fever persist for more than two days than give a course antibiotic by consulting your doctor.
If you find any sign of head injury
like Loss of consciousnesses, Drowsiness
, ENT bleed and vomiting
than immediately go for CT Head in ER.