History:

• 54 yo M w/ PMH of ETOH abuse, schizophrenia, seizure disorder on keppra with questionable compliance presents with seizure
• Per EMS - patient was drinking beer, mowing the lawn (middle of day, 100 ℉, 100% humidity) and began seizing which terminated without intervention
• On arrival patient is still postictal/unresponsive, not able to contribute to history

Physical Exam:

HR 144 BP 58/33 RR 22 O2 98% (on NRB) T 108.6 (core)

•  Patient is completely obtunded and unresponsive
•  Airway grossly patent but rhonchorous with equal breath sounds
•  Skin is warm and dry with weak peripheral pulses
•  No signs of trauma

Bedside Diagnostics:

• Blood glucose: 93

• ECG: Sinus tachycardia with poor baseline, peaked T waves

Differential Diagnosis:

•  Heat stroke (exertional vs non-exertional)
•  Neuroleptic malignant syndrome
•  Thalamic stroke vs ICH vs SAH
•  Intoxication/drug use
•  Serotonin syndrome
• Thyroid syndrome
• Status epilepticus
• Sepsis

Management:

• Immediate and aggressive cooling - bags of ice in groin, axilla, neck while setting up for evaporative and convective cooling (spraying patient with tepid water with large fans blowing cool air at patient)
• Stop cooling at 39 ℃ to prevent afterdrop
• Benzos as needed to prevent shivering (ativan 1-2mg)
• Fluid resuscitate (2-3L) → no change in hemodynamics
• Anticipate and manage complications: hyperkalemia, hypoglycemia, seizures, ARDS, AKI, rhabdomyolysis, shock liver, DIC

Teaching points:

• Heat stroke is life threatening condition (mortality estimated 21-63%) defined by core temperature >104 ℉ (40 ℃) plus neurologic deficit or altered mental status 
• Treatment is immediate cooling: Most effective method: ice bath immersion (not usually practical in ER setting with unstable patients), Effective and practical: evaporative and convective cooling
• Adjuncts: ice packs to neck, axilla and groin; cold IV fluids, cooling blankets

References: Bouchama A et al. Cooling and hemodynamic management in heatstroke: practical recommendations. Crit Care. 2007;11(3):54. Douma M et al. First aid cooling techniques for heat stroke and exertional hyperthermia: A systematic review and meta-analysis. Resuscitation. 2020; 148:173-190. Mehta SR and Jaswal DS. Heat stroke. Med J Armed Forces India. 2003 Apr; 59(2): 140–143.