I have a slight headache and feel sleepy, could this be the start of a cold or flu?

Nonspecific: Your symptoms are nonspecific but could be the prodrome of a viral infection. At this time, rest, take in adequate fluids and take Tylenol. Observe for appearance of sore throat, nausea, vomiting,or diarrhea which are symptoms of the commonest summer viral infections. Check with your MD if you have further questions or more severe symptoms.