If a patient presents with CNS dysfunction but rectal temperature is below 105°F, what is the prudent course of action?

• A. Initiate cold-water immersion immediately
• B. Place in a warm environment and monitor
• C. Administer only oral fluids and transport later
• D. Delay cooling until EMS arrives

Answer: (A)

When CNS dysfunction appears in a patient with potential heat illness, the priority is rapid cooling. CNS signs indicate heat stroke, a medical emergency where brain injury risk rises quickly if cooling is delayed. Cold-water immersion is the fastest, most effective way to lower core temperature in exertional heat stroke, so it should be started immediately in the field. Don’t wait for a higher rectal temperature or for EMS to arrive; start cooling right away while arranging transport for definitive care. Other approaches—warming the patient, delaying cooling, or simply giving oral fluids and delaying care—do not address the urgent need to reduce core temperature and can worsen outcomes.