title: [Stress test at 44 °C and 80 % of humidity and usefulness of ice suit].
abstract: OBJECTIVE
  to compare the fatigue in a stress test at high temperature and humidity in eight healthy volunteers.
  
  
  METHODS
  the time of pedaling on the ergometer cycle was measured to know the exercise's efficiency at 30 km/h until the volunteers presented exhaustion or their heart frequency increased to > 160 beats/min. A basal test in the tunnel's ventilation of the Naica mine at 37.5°C and 40 % humidity was done. We repeated the stress test at the entrance of the cave, where temperature was 44°C and 80 % humidity. We compared using the protector equipment with ice and cold air breathing suit.
  
  
  RESULTS
  the stress test al 44°C and 80 % humidity with the protector suit was interrupted in 75 % of participants because of an increase in the heart frequency (> 160 per minute) The exercise time was duplicated in 62 % and was increased in 100% of the participants with an average increase of 2.25 times and a rank of (1.12-3.3). Using the statistical Wilcoxon test the differences between the times of stress test with and without equipment at 44°C and 80 % humidity had a Z of 2.52 and a p of .012 was done.
authors.affiliation: Proyecto Naica en La Cueva de los Cristales, Chihuahua, México. germangh58@gmail.com
authors.forename: Germán
authors.initials: G
authors.lastname: González-Hidalgo
authors.forename: Hafid
authors.initials: H
authors.lastname: Sánchez-Flores
authors.forename: Guillermo
authors.initials: G
authors.lastname: López-Castellanos
mesh_terms: D000328:Adult; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D007053:Ice; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D007053:Ice