missed ards window (>48hrs) missed mechanical ventilation window (>7 days) refractory hypotension (> 0.2 mcg/kg/min of norepinephrine or equivalent dose for minimum of 6 h) core temperature <35.5°c while not receiving crrt patient is unable to give consent and no legally authorized representative is available; significant, active bleeding (>3u blood products and/or surgical/ir intervention) platelets <10k/mm3 (uncorrected) active hematologic malignancy skin process precludes cooling device moribund, not likely to survive 72h pre-morbid condition makes it unlikely that patient will survive 28 days do not resuscitate status not likely to remain intubated for ≥48h physician unwilling to participate severe underlying lung disease on home o2 on bipap (except for osa) prior lung transplantation bmi >45 kg/m2 known nyha class iv heart disease acute coronary syndrome past 30 days (mi, unstable angina) cardiac arrest within 30 days of enrollment burns over >20% of the body surface severe chronic liver disease (child-pugh of 12-15) previously randomized in chill study

missed ards window (>48hrs) missed mechanical ventilation window (>7 days) refractory hypotension (> 0.2 mcg/kg/min of norepinephrine or equivalent dose for minimum of 6 h) core temperature <35.5°c while not receiving crrt patient is unable to give consent and no legally authorized representative is available; significant, active bleeding (>3u blood products and/or surgical/ir intervention) platelets <10k/mm3 (uncorrected) active hematologic malignancy skin process precludes cooling device moribund, not likely to survive 72h pre-morbid condition makes it unlikely that patient will survive 28 days do not resuscitate status not likely to remain intubated for ≥48h physician unwilling to participate severe underlying lung disease on home o2 on bipap (except for osa) prior lung transplantation bmi >45 kg/m2 known nyha class iv heart disease acute coronary syndrome past 30 days (mi, unstable angina) cardiac arrest within 30 days of enrollment burns over >20% of the body surface severe chronic liver disease (child-pugh of 12-15) previously randomized in chill study

1. missed ards window (>48hrs) 2. missed mechanical ventilation window (>7 days) 3. refractory hypotension (> 0.2 mcg/kg/min of norepinephrine or equivalent dose for minimum of 6 h) 4. core temperature <35.5°c while not receiving crrt 5. patient is unable to give consent and no legally authorized representative is available; 6. significant, active bleeding (>3u blood products and/or surgical/ir intervention) 7. platelets <10k/mm3 (uncorrected) 8. active hematologic malignancy 9. skin process precludes cooling device 10. moribund, not likely to survive 72h 11. pre-morbid condition makes it unlikely that patient will survive 28 days 12. do not resuscitate status 13. not likely to remain intubated for ≥48h 14. physician unwilling to participate 15. severe underlying lung disease 1. on home o2 2. on bipap (except for osa) 3. prior lung transplantation 16. bmi >45 kg/m2 17. known nyha class iv heart disease 18. acute coronary syndrome past 30 days (mi, unstable angina) 19. cardiac arrest within 30 days of enrollment 20. burns over >20% of the body surface 21. severe chronic liver disease (child-pugh of 12-15) 22. previously randomized in chill study

1. missed ards window (>48hrs) 2. missed mechanical ventilation window (>7 days) 3. refractory hypotension (> 0.2 mcg/kg/min of norepinephrine or equivalent dose for minimum of 6 h) 4. core temperature <35.5°c while not receiving crrt 5. patient is unable to give consent and no legally authorized representative is available; 6. significant, active bleeding (>3u blood products and/or surgical/ir intervention) 7. platelets <10k/mm3 (uncorrected) 8. active hematologic malignancy 9. skin process precludes cooling device 10. moribund, not likely to survive 72h 11. pre-morbid condition makes it unlikely that patient will survive 28 days 12. do not resuscitate status 13. not likely to remain intubated for ≥48h 14. physician unwilling to participate 15. severe underlying lung disease 1. on home o2 2. on bipap (except for osa) 3. prior lung transplantation 16. bmi >45 kg/m2 17. known nyha class iv heart disease 18. acute coronary syndrome past 30 days (mi, unstable angina) 19. cardiac arrest within 30 days of enrollment 20. burns over >20% of the body surface 21. severe chronic liver disease (child-pugh of 12-15) 22. previously randomized in chill study