Hot Deserts

1. Survival & Necessary Adaptations for the Human
Body in the Desert
By Maura Ashe

4. Basic Desert Facts
•The hot desert is usually near the
equator.
•It is usually the sandy-Egyptian type of
desert.

5. Extreme Conditions of the Desert
•The seasons are warm throughout the year & very hot in the
summer.
•The winters usually bring little rainfall.
•Temperatures depict daily extremes because the atmosphere
contains little humidity to block the Sun's rays. Desert surfaces
receive a little more than twice the solar radiation received by humid
regions and lose almost twice as much heat at night. Many mean
annual temperatures range from 20-25° C. The extreme maximum
ranges from 43.5-49° C. Minimum temperatures sometimes drop to
-18° C.
•Rainfall is usually low and/or concentrated in short bursts between
long rainless periods. Evaporation rates regularly exceed rainfall
rates. Rain often starts falling and evaporates before reaching the
ground. Rainfall is lowest on the Atacama Desert of Chile, where it
averages less than 1.5 cm. Some years are rainless. Inland Sahara
also receives less than 1.5 cm a year. Rainfall in American deserts
is higher — almost 28 cm a year.

6. MORE SPECIFICALLY…
•The Sahara Desert is the world’s largest desert.
•It spans large parts of North Africa.
•Most rain falls throughout the summer, followed
by some scarce winter rain.
•Animal life of Sahara include gerbil, jerboa, cape
hare and desert hedgehog, barbary sheep, oryx,
gazelle, deer, wild ass, baboon, hyena, jackal,
sand fox, weasel and mongoose.

7. Homeostasis & how it is maintained
•Body temperature for a human = 98.6 degrees.
•Bring iced towels in order to cool down as well as seek shade under
the few trees of the desert.
•Avoid any type of alcohol beverage because it will more than likely
dehydrate the body. The #1 recommendation is water.
•Perspiration will help to keep you cool but excessive sweating will
cause your body temperature to rise. Even if you have plenty of
water, your body is being depleted of salts.
•Stay out of the sun and rest.
•Drink the water you have – don’t save it or your body will weaken.
•Keep clothes on – they provide protection. Shelter from the sun can
be found under your vehicle, a rock ledge, trees or shrubs. A foot
down causes a 20 to 30° drop in temperature.

8. Human Adaptations
•Body temperature in a healthy person can be
raised to the danger point by absorbing heat or
by generating it. Heat can be absorbed from the
ground by reflection or direct contact. Any kind
of work or exercise increases body heat.
•The body gets rid of excess heat and attempts to
keep the temperature normal by sweating, but
by sweating the body loses water and
dehydration results.
•This water must be replaced. Drink cool or warm
water as fast as you want, but cold water may
cause distress and cramps.

9. The Effects of Too Much Exposure
of Heat
•An increase in body temperature of 6 to 8
degrees above normal (98.6) for any
extended period causes death.
•Thirst and discomfort
•Slow motion, no appetite, and later nausea,
drowsiness, and high temperature.
•If dehydration is from 6 to 10 per cent,
symptoms will be: dizziness, headaches, dry
mouth, difficulty in breathing, tingling in arms
and legs, bluish color, indistinct speech and
finally, inability to walk.

10. Three Organ Systems Affected
•Excretory System: Clearly, the amount of water one
takes in correlates with whether or not they are
dehydrated. If someone is not given a sufficient amount
of water, they less frequently urinate which equates to
the storage of unnecessary toxins in their body. It is then
that it becomes dangerous.
•Integumentary: This system generally keeps the organs
from drying out, leaving ample moisture for the body.
When a person is under such extreme heat conditions,
their body becomes weak and their organs eventually
deteriorate.
•Immune: In the desert, a person’s immune system
weakens because the conditions evaporate all the water
in the atmosphere and it is thus nearly impossible to
flush out any disease or illness from the body.

11. Proper Clothing & Special
Equipment Needed
•Avoid any body hugging or synthetic type of clothes.
Don't go out in the sun without putting on a sunscreen
and sunglasses. Also, the night temperature in the
desert falls to a considerable degree.
•Pack thick clothing for nighttime.
•You should carry a mix of woolen and light woolen
clothing.
•Keep a canvas of water handy at all times.
•It is important to remain hydrated but an over excess of
water can also lead to health problems (even death!)