﻿Exercise 
  and 
  Humid 
  Heat 
  upon 
  Pulse 
  Rate, 
  etc. 
  1 
  1 
  3' 
  

  

  heat 
  was 
  investigated 
  upon 
  three 
  subjects, 
  with 
  a 
  view 
  to 
  comparing 
  the 
  

   physiological 
  effects 
  produced 
  by 
  external 
  heat 
  alone 
  with 
  that 
  produced 
  by 
  

   exercise 
  in 
  a 
  hot 
  climate. 
  A 
  small 
  chamber 
  of 
  galvanised 
  iron 
  was 
  used 
  as 
  a 
  

   hot 
  room. 
  The 
  iron 
  was 
  exposed 
  to 
  the 
  direct 
  sun's 
  rays, 
  and 
  additional 
  

   moist 
  heat 
  was 
  produced 
  by 
  boiling 
  water 
  within 
  the 
  chamber 
  ; 
  on 
  sunny 
  

   days 
  a 
  wet 
  bulb 
  temperature 
  of 
  about 
  102° 
  F. 
  could 
  be 
  obtained. 
  The 
  results 
  

   are 
  tabulated 
  separately 
  in 
  Table 
  VII. 
  

  

  In 
  all 
  experiments 
  observations 
  were 
  made 
  upon 
  the 
  changes 
  of 
  pulse 
  rate, 
  

   blood 
  pressure, 
  body 
  temperature, 
  and 
  carbon 
  dioxide 
  content 
  of 
  the 
  alveolar 
  

   air. 
  The 
  pulse 
  was 
  counted 
  for 
  several 
  quarter-minute 
  periods, 
  and 
  in 
  

   general 
  the 
  pulse 
  rate 
  of 
  the 
  subject 
  in 
  a 
  lying 
  position 
  was 
  contrasted 
  with 
  

   that 
  of 
  the 
  subject 
  standing 
  up. 
  

  

  The 
  blood 
  pressure 
  was 
  estimated 
  by 
  means 
  of 
  a 
  Tycos 
  sphygmomano- 
  

   meter, 
  which 
  instrument 
  had 
  been 
  checked 
  against 
  a 
  mercury 
  manometer. 
  

   The 
  body 
  temperatures 
  recorded 
  denote 
  invariably 
  rectal 
  temperatures. 
  

   The 
  alveolar 
  air 
  was 
  sampled 
  by 
  the 
  Haldane-Priestley 
  method. 
  

  

  Pulse 
  Bate. 
  — 
  The 
  pulse 
  rate 
  (Table 
  I) 
  in 
  the 
  subject 
  at 
  rest 
  was 
  within 
  the 
  

   range 
  considered 
  normal 
  for 
  a 
  temperate 
  climate, 
  varying 
  between 
  68 
  and 
  98 
  

   per 
  minute. 
  The 
  pulse 
  rate 
  determined 
  in 
  an 
  upright 
  and 
  recumbent 
  position 
  

   showed 
  now 
  and 
  again 
  a 
  considerable 
  difference, 
  being 
  lower 
  in 
  several 
  of 
  the 
  

   subjects 
  when 
  lying 
  down 
  ; 
  considerable 
  individual 
  variations 
  in 
  this 
  respect 
  

   were 
  noted. 
  

  

  The 
  increase 
  caused 
  by 
  exercise 
  corresponded 
  roughly 
  with 
  the 
  violence 
  of 
  

   the 
  effort, 
  and 
  in 
  those 
  experiments 
  in 
  Table 
  I 
  where 
  the 
  subject 
  raced 
  up 
  

   and 
  down 
  stairs, 
  the 
  rise 
  accorded 
  with 
  the 
  length 
  of 
  time 
  taken 
  in 
  perform- 
  

   ing 
  the 
  task. 
  The 
  pulse 
  rate 
  began 
  to 
  fall 
  again 
  immediately 
  the 
  exercise 
  

   was 
  discontinued, 
  rapidly 
  at 
  first 
  and 
  more 
  slowly 
  afterwards, 
  and 
  after 
  five 
  

   minutes 
  or 
  so 
  the 
  pulse 
  rate 
  was 
  still 
  above 
  the 
  rate 
  at 
  rest. 
  

  

  In 
  the 
  walking 
  exercises, 
  extending 
  over 
  a 
  prolonged 
  period, 
  the 
  pulse 
  rate 
  

   at 
  the 
  end 
  of 
  the 
  experiment 
  was, 
  as 
  a 
  rule, 
  high, 
  and 
  it 
  took 
  a 
  much 
  longer 
  

   time 
  to 
  return 
  to 
  the 
  original 
  rate. 
  In 
  a 
  few 
  instances 
  the 
  pulse 
  rate 
  was 
  

   determined 
  after 
  half 
  the 
  walk 
  had 
  been 
  accomplished, 
  and 
  it 
  was 
  observed 
  

   that 
  during 
  the 
  second 
  half 
  of 
  the 
  exertion 
  practically 
  no 
  further 
  rise 
  was 
  

   produced. 
  In 
  the 
  special 
  walking 
  experiment 
  (see 
  chart) 
  the 
  pulse 
  of 
  the 
  

   subjects 
  I 
  and 
  II 
  showed 
  a 
  rapid 
  and 
  marked 
  rise 
  at 
  first 
  ; 
  afterwards 
  the 
  

   pulse 
  rate 
  continued 
  to 
  rise 
  at 
  a 
  much 
  slower 
  rate, 
  or 
  exhibited 
  only 
  insignifi- 
  

   cant 
  variations. 
  

  

  In 
  the 
  hot 
  room 
  experiments 
  the 
  pulse 
  rate 
  rose 
  very 
  slowly 
  and 
  gradually 
  

   concomitantly 
  with 
  the 
  body 
  temperature. 
  

  

  Blood 
  Bressure. 
  — 
  The 
  results 
  of 
  the 
  estimations 
  of 
  blood 
  pressure 
  are 
  

  

  