Unit 3 - Ambient Environment Flashcards
Describe our physiological responses to changes in temperature in the ambient environment.
Physiological responses from changes in temperature work to do so to keep body temperature around 37 degrees Celsius. Adaption of core temperature is achieved through metabolism.
Warmer Temperature’s: Peripheral vasodilation at temperatures slightly above the ideal to increase loss of heat through convection or radiation, higher temperatures produce sweating to increase heat loss through evaporation, and activity may slow to reduce heat production.
Cooler Temperatures: Milder cooling can be tolerated through increased metabolic rate, but further cooling require behavioral/physiological reactions that either increase heat production or decrease heat loss.
Methods to increase heat production include: increased muscular activity, shivering, and complex metabolic thermogenesis.
Heat loss is reduced in body extremities through peripheral vasoconstriction that reduces blood flow (and thus loss through convection) and through behaviors such as huddling.
What are the symptoms of heat stress (heat exhaustion and heat stroke) and hypothermia?
Heat stress occurs when the body is unable to restore body temperature to normal, which then makes several issues to occur.
The mildest issue is heat exhaustion, characterized by faintness, nausea, vomiting, headache, headache and restlessness.
More serious and life-threatening is heat stroke, which is characterized by confusion, staggering, headache, delirium, coma, and eventually death. In this illness, the sweating mechanism is broken down and immediate cooling (such as ice water) is necessary for survival.
Finally, heat stress may induce heart attack due to the excessive strains on the cardiovascular system in the thermoregulatory process.
Hypothermia is analogous to heat stress for cold climates
As the core body temperature approaches 32 Celsius, shivering is replaced by muscular rigidity, confusion, and eventually loss of consciousness. If warmth is not restored coma and death from heart attack follow.
List the physical and personal factors that influence the impact of personal thermal stress.
Physical factors that may increase the risk of thermal stress include: air speed (velocity of air may increase heat loss if below body temperature or vice vera if above), humidity (reduces the efficiency of heat loss through evaporation), clothing (provides varying degrees of insulation and may retard heat loss), and acclimatization.
What is acclimatization? How does acclimatization influence a person’s response to temperature?
Acclimatization: Is the increased physiological tolerance after continued exposure to high or low environments. It helps us adapt to our environment’s so our core body temperature can be maintained more efficiently.
Acclimatization may influence a persons response to temperature by increasing sweating efficiency in hotter locations that reduces discomfort and heart rate, reduced body temperature, and higher volumes of sweat with reduced concentrations of salt.
Acclimatization for cold temperatures are also enhanced by natural selection (some have increased genetic capacity). Acclimitization for these environemtents include reduced shivering (enhanced non-shivering physiological response to generate heat), peripheral vasoconstriction (for maintaining heat in extremities), and reduced discomfort.
Efficiency of acclimatization may be effect by genetics and behavioral factors.
What is a modal comfort envelope?
Modal Comfort Envelope (MCE) allows for a range of ambient conditions that will provide comfort for most people.
The upper and lower levels of the envelope with relative humidity at 45% are 27C(80F) and 24C(76F). These values consider relatively low value of clo (moderate clothing on) and sedentary activity.
These levels are considered to work across cultures as research into cultural differences in comfortable temperatures do not differ substantially.
Is there conclusive research evidence that heat has an effect on task performance? Explain your answer.
There is ample evidence showing that heat can effect task performance however, these effects are modulated by various factors.
Research shows that sufficiently high ambient temperatures hurt performance, although other studies show that higher temperatures may actually help performance and then later hurt it, whereas other studies show the reverse pattern.
Performance is more affected by un-acclimatized then acclimatized, performance is affected depending on type and number of tasks performed simultaneously (with more complex and number of tasks facing greater decriment)
Studies on decrements from heat: Millitary members exposed to high ambient temperatures had deteriorated performance on vigilance and so on, performance usually detracts after 2 hours or sooner depending on the temperatures.
Although heat may briefly improve performance on reaction time (although soon dissipates). Whereas auditory attention under heat showed decrements and the improvement’s.
Is there conclusive research evidence that low temperatures have effects on task performance? Explain your answer.
Cooling of the body can increase difficulty and performance through effects on the extremities (due to these areas dramatic cooling responses) and decrease performance of fine motor tasks, tactile sensitivity, dexterity, and strength.
Drops in mental ability (learning, vigilance, attention, short term-memory, estimation of time etc.) may occur with cooler temperatures and cooling of central areas.
Children were performing optimally at comfortably cool temperatures. - Additionally, sudden coolness may be arousing and temporarily enhance performance.
Compare the theories about the impact of temperature on behaviours.
Modulating factors such as body temperature (actual temperature of body may affect performance, however is rarely measured in research), arousal (temperatures may affect optimal arousal level - effects such as initial increase of warmth followed by decrease with adaption), attention (resource expenditures of adaption may cause narrowing of attention), and perceived control (perceived control can reduce negative effects of environmental stressors) likely modulate the mixed findings.
Summarize the influences of ambient temperature on social behaviours.
Attraction: College students exposed to varying temperatures, cool temperatures increased attraction, whereas heat and crowding reduced attraction - although other research complicates this, heat may have negative impact on attraction to strangers but not on those who are similar.
Heat and Aggression - Hot temperatures correlate with greater crime rates and riots. However, laboratory studies show mixed results which may be explained through experienced negative affect which when moderate supports aggression but when greater detracts it through lethargy or otherwise. Additionally, other correlates to hot weather such as increased consumption of alcohol, being couped up or perceived loss of control, or being off from school may also mediate these behaviors.
Heat and Helping Behavior: Heat seems to have a negligible effect on helping behavior as it seems that discomfort from ambient temperature can both help and hinder helping behavior.
Cold and Social Behavior: Very little is confirmed although similarities to heat and aggression may exist in a similar affective way.
Define noise. What factors characterize a sound labelled as noise?
Noise is defined as unwanted and disturbing and is therefore likely to be judged unpleasant (unwanted, uncontrollable, and unpredictable sound).
Define temporary threshold shift and permanent threshold shift.
The usual index of hearing loss for a given frequency is the number of decibels above the normal threshold for the sound to be heard. In other words, there is a shift in the hearing threshold.
Noise-induced hearing loss can be temporary (up to 16 hours) or permanent. These effects are commonly called temporary threshold shifts (TTS) and permanent threshold shifts (PTS)
Outline any effects of noise on health, especially on hearing loss.
Noise-induced hearing loss is characterized by the loss of auditory sensory cells in the cochlea in the inner ear, which cannot be regenerated. Loud and prolonged sound is consistently shown to lead to hearing loss
Unwanted and annoying sounds are stressful and enable potentially damaging physiological reactions to stress (release of hormones, rise in blood pressure, change in heart rhythm). Prolonged stress may damage organs i.e. permanent ailments in cardiovascular system and what not. -mediated by perceived sense of control/learned helplessness.
Noise has been additionally linked to hypertension, cardiovascular disordered, ulcers, heart disease, and sleep disturbance. Stress caused by uncontrollable noise may also pose a immunological risk. Noise also cause lowered quality of life and increased blood pressure in children, increased risk for hearing loss from postnatal exposure as well as birth defects.
Disruption of sleep causes negative mood, inattentiveness, and lowered performance. Additionally, noise disrupts mental wellbeing: Anger being a big one, depression, and mental instability. - noise can seriously affect the mental stability of people.
Outline the effects of environmental noise on children’s language, cognitive development, and learning.
children from noisier homes had impaired cognitive and language development compared to those from quitter households. - chronic exposure in classroom has been associated with poorer reading abilities. Childrens living in the same apartment but in quiter areas had better reading scores then those living near the noisier lower level floors. Whereas a classroom with both a noisier and quiteir side showed the noisy side to be far behind. - noise makes it harder for children to think and slows down their learning.
What are the aftereffects of noise?
Laboratory research on the effects of noise on task performance has shown mixed results. Whether a noise has a positive or negative effect, or no effect at all, depends on a range of variables, such as intensity, predictability, controllability, and the type of tasks performed. Apparently noise can affect the performance of some tasks after the fact. “Aftereffects” of noise, such as poorer performance and a lower tolerance for frustration, can be as severe as the effects during exposure to noise
List the effects of community noise on residents’ behaviours and well-being. How do people cope?
Some argue that growth of noise in the community has normalized noise making and apathy between neighbours. A implied right to make noise worsens noise in communities, creates conflicts between peoples, and worsens health physically and mentally.
The rise of noise will become a future health crisis.
