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Environmental · Adult / adolescent · ALS

Adult heat illness / hyperthermia

Move promptly to cooling and escalate when mental status or perfusion is abnormal.

OCEMS source summary · Updated 2026-09-16

Key cautions & base contact

  • Do not give oral fluids to someone who cannot safely protect the airway.
  • Pediatric fluid doses and required base contact differ; use the pediatric thermal guide.

Recognize severity

  • Mild/moderate features include malaise, tachycardia, nausea, or vomiting while conscious. Confusion/altered consciousness, hot dry skin, or hypotension activates the severe pathway.
  • Assess the exposure, work/exertion, fluid intake, medications, mental status, and circulation. Reassess frequently for progression.

Mild or moderate illness

  • Move away from the heat to shade/cooler air with good airflow; use a fan when available.
  • Encourage water or a balanced electrolyte drink without caffeine/stimulants if oral intake is safe. Use cool wet towels or cold packs as tolerated.

Severe illness

  • Check SpO₂ and provide the source’s oxygen support when room-air saturation is below 95%.
  • For hypotension/poor perfusion with clear lungs/no CHF, give saline 250 mL IV and reassess; repeat to a maximum 1 L to support perfusion.
  • Use available active or passive cooling, including cold packs at the axillae, posterior neck, and groin, plus airflow with appropriate skin exposure.

Transport and reassessment

  • Provide ALS escort to the nearest appropriate ERC; contact base if further stabilization orders are needed.
  • Continue cooling and monitoring during transport. Report mental-status and perfusion trends, exposure, cooling methods, fluids, and treatment response.