Hot Adaption and Acclimation Tutorial

Question 1

What is one of the main difficulties in evaluating population differences in heat acclimation? How is this rectified?

Answer 1

• The diversity of techniques and reference populations.
• Researchers evaluate thermoregulatory responses to work in heat stress of different populations under the same conditions of temperature and workload

Question 2

Bantus: Environment?

Answer 2

Summer: 25˚C min 31.1˚C max

Relative humidity: 45-68%

Question 3

What are the anthropometric characteristics of the Bantus population in comparison to white populations?

Answer 3

• Shorter
• Lighter
• Leaner
• Greater surface area per unit of body

Question 4

Bantus vs white exercise hot test results

Answer 4

Bantus: 20/20 completed
White: 10/20 completed
Acclimated and non-acclimated Bantus sweated at lower rate + maintained lower rectal temperature + maintained lower heart rate.

Question 5

Bushmen: Location

Answer 5

Kalahari Desert

Question 6

Bantus Location:

Answer 6

Central and sub-sahara africa

Question 7

Bushmen: Location Temperature

Answer 7

Kalahari:
Summer: 18˚C min 32.5 ˚C max
Winter: 3.2˚C min 22.5 ˚C max

Question 8

Bushmen: Environment

• Annual rainfall
• Highest recorded temp

Answer 8

Annual Rainfall: 400-600mm

Highest temp <60˚C

Question 9

What is the most important factor for bushmen subsistence:

Answer 9

Distribution of waters sources

Question 10

What is the predominant food of the Bushmen?

Answer 10

Mongongo nut - hella energy

Question 11

Bushmen diet:

Answer 11

1/3 mongongo, 1/3 meat, 1/3 veg

Question 12

Which population do the river Bushmen have similar genetic constitution to and why?

Answer 12

• Bantu population due to proximity and hybridisation.

Question 13

Difference between Desert and river bushmen

Answer 13

Desert bushmen shorter and lighter. Greater SA/Wt then river bushmen.

Question 14

Compare the thermoregulatory characteristics of white populations, river and desert bushmen.

Answer 14

River/Desert - Bushmen have similar sweat and rectal temperatures
Desert B = Lower heart rate
Rectal temp and HR of all busmen intermediate of acclimated and non-acclimated white pop.
Bushmen as whole sweat less than whites.
BUSHMEN PARTIALLY ACCLIMATED

Question 15

Aboriginal: Environment?

Answer 15

Summer 22˚C min 37˚C Max

Winter: 4˚C min 21˚C max

Question 16

What is the subsistence economy of Indigenous populations?

Answer 16

• Capture of small game and gathering of wild roots and fruit plants.

Question 17

Are Bushmen or Indigenous Australian’s in a more ‘stressful’ environment in terms of resources, water availability and presence of high temperatures?

Answer 17

Australian Indigenous

Question 18

Bantus, Bushmen, Aboriginal anthropometric characteristic comparison:

Answer 18

Aboriginal = Tallest of three (Tall as white population), lightest in weight of the three, thus Aboriginal populations have the highest SA/Wt ratio (sans desert bushmen)

Question 19

Compare the thermoregulatory characteristics of the Indigenous Australians to the Bantus, Bushmen and white populations.

Answer 19

• Rectal temp + HR higher than acclimated whites.
• Sweat rates lower than acclimated whites
• Similar results to Bantus and Bushmen

Question 20

Chaamba Arabs: Location

Answer 20

Sahara

Question 21

Sahara vs Kalahari environment:

Answer 21

Saha has higher temperatures and lower humidity.

Question 22

Chaamba Arabs: Environment

• summer temps,
• annual rainfall

Answer 22

Sahara:

• Summer: 26˚C min 37.5˚C max
• Annual Rainfall: 100mm

Question 23

Compare the anthropometric characteristics of the Chaamba Arabs to whites:

Answer 23

• CA has higher SA-Wt ratio

- 2.91 vs. 2.60 cm2/kg`

Question 24

Compare the thermoregulatory characteristics of the Chaamba Arabs (and French whites for this experiment) to the acclimated whites from the African experiments:

Answer 24

• CA and french whites had higher rectal temperatures and higher heart rates.
• In last 2hrs, CA had lower sweat rates than French whites
• CA response to heat stress inferior to whites

Question 25

Why do Chaamba Arabs have poorer thermoregulatory responses to heat than the white control population:

Answer 25

• Poor physical conditioning
• CA clothing reduces heat stress by trapping stale air between skin and cloth → Insulates skin from ambient temperature and solar radiation.
• Thus protected themselves effectively enough that normal state has seldom exposure to heat stress temperatures/prolonged dehydration.
• Cultural adaption, not physiological