Which observation may indicate a client is experiencing opioid intoxication?

The observation of small pupils, also known as miosis, is a classic indicator of opioid intoxication. Opioids have a significant effect on the nervous system, and one of their hallmark symptoms is the constriction of the pupils. This occurs because opioids activate the parasympathetic nervous system, resulting in a decrease in pupil size. It is essential in clinical scenarios to recognize this symptom as it can help differentiate opioid intoxication from other substances that may cause different physiological responses.

Other options like concern over personal safety may not specifically indicate opioid intoxication, as this concern can arise in various contexts and substance use scenarios. Rapid heartbeat may suggest stimulant use rather than opioid intoxication, as opioids typically lead to bradycardia (a slower heartbeat) rather than tachycardia. High fever is also not characteristic of opioid effects; it can indicate a variety of medical conditions unrelated to opioid use. Thus, the presence of small pupils is a key sign that signifies opioid intoxication.