Two collapsed runners, one ice bath too few

Runner 1 is exertional heat stroke - core temperature >40°C plus central nervous system dysfunction. This is a time-critical emergency where minutes of cooling translate into survival and organ function.

Cool first, transport second.

• Call the ambulance immediately, stating 'exertional heat stroke, cooling on site' - but do not let transfer delay cooling.
• Cold-water immersion now (ice bath, water 2–10°C, stirred, with the trunk and limbs submerged, head supported). Target 38.5–39.0°C; at immersion rates of ~0.15–0.35°C/min, expect 10–20 minutes from 41.3°C. Measure rectal temperature every 5 minutes and stop at target.
• Staff the bath continuously; monitor airway, and be ready for seizure or vomiting. Give oxygen, IV crystalloid, check glucose.
• Do not give antipyretics - the hypothalamic set point is normal; they do not work and risk hepatic injury.

Runner 2 is not a heat-stroke case by numbers. Confusion with a core temperature of 38.1°C and excessive drinking points to exercise-associated hyponatraemia. Do not put him in the second ice bath; check point-of-care sodium and glucose. If he is symptomatic, give 3% hypertonic saline 100 mL IV, repeated as needed, and restrict free water.

Logistics. One bath each is the correct allocation only if the second bath is used for cooling - it is not. The remaining bath stays available for the next case, and you escalate now for more staff and ambulances rather than at 40 minutes.

Confirmation. Point-of-care sodium (glucose too, since hypoglycaemia mimics confusion). Hyponatraemia with a history of drinking beyond thirst during a long race, weight gain, and confusion is EAH until disproved. Check for signs of cerebral oedema - reduced consciousness, vomiting, seizure - and record weight if a scale is available.

Treatment thresholds.

• Symptomatic (confusion, seizure, coma): 3% saline 100 mL IV bolus, repeated up to three times, aiming for symptom reversal rather than a target sodium. Do not give hypotonic fluid; do not simply restrict fluids and watch in a confused athlete.
• Asymptomatic or mildly symptomatic: restrict oral intake, monitor, and recheck sodium.
• Do not correct rapidly beyond symptom relief, to avoid osmotic demyelination.

Look-alikes to exclude: heat stroke (repeat rectal temperature - a normal temperature excludes it), hypoglycaemia, head injury from a fall, drug use (stimulants, MDMA) which can cause both hyperthermia and hyponatraemia.

Prevent the next case. Post-race messaging, pre-race briefing on drinking to thirst, and a weight-check station are worth more than any treatment protocol. Flag the event's fluid advice for review.

Minimum recovery. Exertional heat stroke causes rhabdomyolysis, hepatic injury, coagulopathy and acute kidney injury, and these can evolve over 24–72 hours. He needs hospital observation, serial CK, renal and liver function, and coagulation studies.

Before any exercise:

• CK and transaminases normalising, not just 'improving'.
• No ongoing coagulopathy or renal impairment.
• A face-to-face review with an explanation of what happened and why.

Graded return.

• Walking then easy running in cool conditions first, over 2–8 weeks depending on severity.
• Avoid heat and humidity for the first weeks; reintroduce heat gradually and only with guidance.
• Stop and seek help for confusion, unusual fatigue, dark urine or reduced urine output.

Counselling points.

• He was not simply 'dehydrated' - he overheated, and his risk of recurrence is not trivial.
• Drink to thirst; over-drinking is now a documented risk for him.
• Sleep, pacing and pre-cooling matter more than supplements.
• Consider a heat tolerance test before returning to racing in the heat, and flag any residual temperature-regulation problems to a sports physician.