I don't really get what your asking. If you do a shot of heroin and instantly start feeling feverish and shitty that is "cotton fever" meaning slang for a fiber of cotton entering your blood stream. In reality cotton fever is usually caused by the introduction of a foreign bacteria to the body i.e. from contaminated needles, old cottons, bad batch of dope, etc..
Withdrawal happens when you abstain from use. You do not develop cotton fever 24 hours after your shot...