Mortality from exertional heat stroke is low (<5%), as it typically affects young healthy people and is recognised and treated promptly. Conversely, mortality from heat stroke in older adults can exceed 50%.[10]Epstein Y, Yanovich R. Heatstroke. N Engl J Med. 2019 Jun 20;380(25):2449-59.
https://www.nejm.org/doi/10.1056/NEJMra1810762
http://www.ncbi.nlm.nih.gov/pubmed/31216400?tool=bestpractice.com
The prognosis of heat stroke in adults depends on several factors, such as the amount of time the patient remains at an elevated core temperature and the extent of hyperthermia. All severe complications of heat stroke are increased in relation to this. Patient comorbidities are also important. Other poor prognostic indicators include prolonged coma or shock, presence of rhabdomyolysis and more severe end-organ damage, elevated creatine kinase >1000 IU/L, and development of pulmonary complications, including acute respiratory distress syndrome.[27]Varghese GM, John G, Thomas K, et al. Predictors of multi-organ dysfunction in heatstroke. Emerg Med J. 2005 Mar;22(3):185-7.
https://emj.bmj.com/content/22/3/185
http://www.ncbi.nlm.nih.gov/pubmed/15735266?tool=bestpractice.com
[28]Yamamoto T, Fujita M, Oda Y, et al. Evaluation of a novel classification of heat-related illnesses: a multicentre observational study (Heat Stroke STUDY 2012). Int J Environ Res Public Health. 2018 Sep 8;15(9):1962.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165559
http://www.ncbi.nlm.nih.gov/pubmed/30205551?tool=bestpractice.com
Patients with a history of heat stroke may be more likely to have heat stroke again. Heat stress testing can aid in quantifying risk.[29]Epstein Y. Heat intolerance: predisposing factor or residual injury? Med Sci Sports Exerc. 1990 Feb;22(1):29-35.
http://www.ncbi.nlm.nih.gov/pubmed/2406544?tool=bestpractice.com
[30]Johnson EC, Kolkhorst FW, Richburg A, et al. Specific exercise heat stress protocol for a triathlete's return from exertional heat stroke. Curr Sports Med Rep. 2013 Mar-Apr;12(2):106-9.
http://www.ncbi.nlm.nih.gov/pubmed/23478561?tool=bestpractice.com
[31]Druyan A, Makranz C, Moran D, et al. Heat tolerance in women - reconsidering the criteria. Aviat Space Environ Med. 2012 Jan;83(1):58-60.
http://www.ncbi.nlm.nih.gov/pubmed/22272518?tool=bestpractice.com