Dear editor: The present is a prospective and observational study from the patients admitted to Mexicali’s General Hospital with confirmed diagnosis of heat stroke between June 2011 and September 2014. The purpose of this article is to show the mortality of this condition and demonstrate in a simple way the degree of disability in the survivors.

Heat stroke is a condition that occurs in individuals exposed to high ambient temperatures, who develop hyperthermia greater than 40°C, and severe dehydration with altered mental status.¹

We included 29 cases with heat stroke diagnosis, showing a lethality of 44.8% of the patients admitted. Patients with a high grade of functional impairment were classified with the Glasgow outcome score (GOS) to assess the grade of functionality at their discharge.² We compared our findings with previous essays in Saudi Arabia, where mortality up to 50% have been reported. Both results are similar.¹ A previous trial executed in our hospital reported a mortality up to 37%.³ In that study, there was a higher number of study subjects that fulfilled heat stroke criteria: 78 patients compared with 29 in this trial. The number of cases has been decreasing, probably because of the actions implemented by the government. Between 2006 and 2010, the range was 0.8 to 5.2 cases per every 100 000 people, whereas in this study there were 5.2 to 1.2 cases per every 100 000 people. However, heat stroke continues in spite of the existence of effective preventive measures.

It is important to underline that all variables were associated in a significant way. Patients with a Glasgow coma scale below eight points and previous history of drug abuse increased their risk of organic dysfunction. These two factors had a strong negative correlation with the GOS. This correlation could be used for future investigation.

Up to 17% of the patients who were discharged had a kind of disability and required support to perform basic functional daily life duties, such as eat, work or going to school. Heat stroke is an illness with high lethality, and disability in those who survive. Only 37.9% had a favorable recovery at their hospital discharge (figure 1).

Figure 1 Total of patients from the admitted with the confirmed diagnosis of heat stroke, classified with the Glasgow outcome scale (1=death, 2=persistent vegetative state, 3=serious disability, 4=moderate disability and 5=good recovery). Hospital General de Mexicali, Mexicali, Baja California, México, 2011-2014.  

Pathologies associated to ambient conditions will become more frequent due to their association with global warming. Geographic zones that are not considered warm will be exposed to higher temperatures. There will be a higher risk of developing heat stroke in population that is not acclimated to these conditions, with also higher possibilities for a fatal outcome or disability sequels.