What is the most common cause of a urinary tract infection?

Choice A reason: Acetaminophen reduces fever by acting on the hypothalamic thermoregulatory center but is ineffective for heat stroke, a hyperthermic emergency caused by environmental heat overload. It does not address core temperature elevation or systemic effects like dehydration and organ dysfunction, making it inappropriate for immediate heat stroke management.

Choice B reason: Removing the client’s clothing facilitates evaporative and convective cooling, critical in heat stroke where core body temperature exceeds 40°C. This intervention enhances heat dissipation from the skin, reducing the risk of organ damage from hyperthermia. It is a primary nursing action to lower body temperature effectively and safely.

Choice C reason: Placing a client with heat stroke in a hot bath would exacerbate hyperthermia, worsening organ damage and cardiovascular strain. Heat stroke requires rapid cooling via cold water immersion or evaporative methods, not additional heat exposure, making this intervention dangerous and contraindicated in this life-threatening condition.

Choice D reason: Encouraging oral fluids like cold water is inappropriate for a lethargic heat stroke patient, who may have impaired swallowing or consciousness, risking aspiration. Intravenous fluids are preferred to correct dehydration and electrolyte imbalances safely, as oral intake does not address the urgent need for rapid cooling and systemic stabilization.

Choice A reason: Pyrexia (fever) occurs when pyrogens, like cytokines (IL-1, IL-6), released during infection or inflammation, act on the hypothalamus to raise the body’s temperature set point. This triggers heat production via shivering and vasoconstriction, conserving heat to create a fever, enhancing immune response. This statement accurately describes the primary mechanism of pyrexia.

Choice B reason: Peripheral vasoconstriction occurs during fever to conserve heat but is a response, not the cause, of pyrexia. It results from hypothalamic signaling after pyrogens reset the thermostat. This statement is inaccurate, as vasoconstriction is a secondary effect, not the initiating physiologic mechanism of fever development.

Choice C reason: Fever increases, not decreases, metabolic rate to generate heat via thermogenesis. Pyrogens elevate the hypothalamic set point, prompting energy expenditure through shivering and muscle activity. This statement is inaccurate, as reduced metabolism would lower body temperature, counteracting the fever response triggered by infection or inflammation.

Choice D reason: Prostaglandin synthesis, particularly PGE2, in the hypothalamus is stimulated by pyrogens, raising the temperature set point to cause fever. Inhibiting prostaglandin synthesis (e.g., by NSAIDs) reduces fever, not causes it. This statement is inaccurate, as prostaglandin inhibition opposes the physiologic mechanism of pyrexia.