(a) "Drug or alcohol overdose" or "overdose" means an acute condition including, but not limited to, physical illness, coma, mania, hysteria or death, which is the result of consumption or use of a controlled substance or alcohol and relates to an adverse reaction to or the quantity of the controlled substance or alcohol or a substance with which the controlled substance or alcohol was combined; provided that a patient's condition shall be deemed to be a drug or alcohol overdose if a prudent layperson, possessing an average knowledge of medicine and health, could reasonably believe that the condition is in fact a drug or alcohol overdose and (except as to death) requires health care.

(b) "Health care" means the professional services provided to a person experiencing a drug or alcohol overdose by a health care professional licensed, registered or certified under title eight of the education law or article thirty of the public health law who, acting within his or her lawful scope of practice, may provide diagnosis, treatment or emergency services for a person experiencing a drug or alcohol overdose. 4. It shall be an affirmative defense to a criminal sale controlled substance offense under this article or a criminal sale of marihuana offense under article two hundred twenty-one of this title, not covered by subdivision one or two of this section, with respect to any controlled substance or marihuana which was obtained as a result of such seeking or receiving of health care, that:

(a) the defendant, in good faith, seeks health care for someone or for him or herself who is experiencing a drug or alcohol overdose or other life threatening medical emergency; and

(b) the defendant has no prior conviction for the commission or attempted commission of a class A-I, A-II or B felony under this article. 5. Nothing in this section shall be construed to bar the admissibility of any evidence in connection with the investigation and prosecution of a crime with regard to another defendant who does not independently qualify for the bar to prosecution or for the affirmative defense; nor with regard to other crimes committed by a person who otherwise qualifies under this section; nor shall anything in this section be construed to bar any seizure pursuant to law, including but not limited to pursuant to section thirty-three hundred eighty-seven of the public health law. 6. The bar to prosecution described in subdivisions one and two of this section shall not apply to the prosecution of a class A-I felony under this article, and the affirmative defense described in subdivision four of this section shall not apply to the prosecution of a class A-I or A-II felony under this article.