Determine nutritional requirements in hot environments, Biology

Assignment Help:

Determine Nutritional Requirements in Hot Environments?

Hot environments may be of two types: dry hot, as in the case of deserts or hot and humid in tropical rain forests and coastal regions. Factors other than air temperature determine physiological strain imposed by the heat stress. These factors include individual variations in body size and fatness, acclimatization, and external factors such as air currents, heat gain due to radiation, intensity of work, clothing and relative humidity. Various practical heat stress indices (e ,g. wet bulb-globe temperature, Heat Stress Index) make use of# ambient temperature, radiant heat and relative humidity to evaluate the environmental potential heat challenge for humans working under that environment. Refer to Table 18.8, which highlights the effects of heat stress.

455_Nutritional Requirements in Hot Environments.png

However, it is important to know that an adequate fluid replacement overshadows all other considerations of nutrient requirements for work in a hot environment. Drinking adequate amount of water at regular intervals prevents dehydration, heat, illness and maintains work performance. Heat acclimatization relatively has no effect on water requirements. Thirst is a poor indicator of hydration status: Intense thirst is usually noticed at 5 to 6% body weight loss due to hypohydration (removal of water). By this time, the physical performance is compromised. Severe hypohydration can-lead to a decreased blood volume and an increase in the plasma osmolality, which can result in decreased sweating and heat dissipation.

Eighty percent of the energy metabolized during exercise in hot environment is liberated as heat (only 20% is utilized as mechanical work) and 80-90% of heat dissipation during work in a hot-dry environment is accomplished by the evaporation of sweat. Each millilitre of sweat evaporated from the skin leads to heat loss of approximately 0.6 Kcal. Sweat rates vary to a great extent from at1 individual to individual, but can reach 2 L/h for prolonged time periods. Hypohydration depends in a large part upon sweat rate, which, in turn, is determined by workload and duration. Other environmental factors are solar load, wind speed, relative humidity and clothing, The influence of these factors on water requirement is given in above Table.


Related Discussions:- Determine nutritional requirements in hot environments

What is demographic transition, What is Demographic Transition? The who...

What is Demographic Transition? The whole process of change with regard to population size and characteristics is called demographic transition. In order to understand this ter

Colonial , 1. The level of organization intermediate between unicellular an...

1. The level of organization intermediate between unicellular and the multicellular - organisms are composed of multiple cells but these fail to exhibit specialization of those cel

Introduction to ecology, Ecology is a interdisciplinary branch of science t...

Ecology is a interdisciplinary branch of science that deals with inter relationship between living organism and their environment. The term ecology (from greek, oikos-meaning ho

Assessment of tubercular meningitis, Assessment   For assessment of cli...

Assessment   For assessment of clinical manifestation of the disease you need to understand three stages of clinical course of the disease which are as follows:  Prodromal

What is genetic engineering, Q. What is genetic engineering? Genetic en...

Q. What is genetic engineering? Genetic engineering, It is also known as molecular cloning or gene cloning, is artificial recombination of nucleic acid molecules in a test tube

Reproduction, What is the difference between asexual and sexual reproductio...

What is the difference between asexual and sexual reproduction

How many chromosomes and dna molecules found per cell, A cell in G1 of inte...

A cell in G1 of interphase has 12 chromosomes. How many chromosomes and DNA molecules will be found per cell when this original cell progresses to the G2?

Show common contraindications of the contraceptive pills, Q. What are the c...

Q. What are the common contraindications of the contraceptive pills? There are medical reports associating the use of contraceptive pills with vomiting, headaches, vertigo, nau

Digestive system, Digestive system is one of eleven major body organ syste...

Digestive system is one of eleven major body organ systems in animals; it converts food from the external environment into the nutrient molecules which can be used and stored by t

Describe three ways that rna differs from dna, Describe three ways that RNA...

Describe three ways that RNA differs from DNA. RNA is single stranded; DNA is double stranded all of the codons from the deletion point to the end of the transcript would be s

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd