Symptomatic treatment you can give but the symptom complex you are explaining can have many differential diagnosis:
-Simple gastroenteritis (usually will not have fever unless child also have loose motions)
-Malarial fever
-Dengue fever
-Flu fever
-meningitis.
Next Steps
meet physician/Pediatrician once and get prescribed medicine, and/or investigation of child if he/she suspects any of major illnesses except simple gastroenteritis.
Health Tips
Just for emergency management
u can give crocin for fever but the dose depends on weight which is not mentioned in your description.
at 8 mths with fever of 102°f you should meet Pediatrician at the soonest to r/o major diseases.