If you have a throat infection then your doctor will most probably prescribe an antibiotic for a speedy recovery.
Individuals who suffer from asthma and other lung diseases caused due to smoking might need antibacterial treatment.
If your fever lasts for more than a week then you can consult a doctor before taking antibiotics. Seeking the advice from a doctor is important because he might suggest you alternative methods like he might give you a suppressant for dealing with cough or inhaler to solve your issue quickly. This might negate the need for antibiotic use.
Doctors used to prescribe antibiotics for every cold and cough issue earlier but considering their various side effects, the use of antibiotics has gone down significantly these days.