Are reptiles affected by wind chill?

[edro]

Windchill: a still-air temperature that would have the same cooling effect on exposed human skin as a given combination of temperature and wind speed.
From: http://www.islandnet.com/~see/weather/life/windchill.htm

As warm-blooded animals, or poikilotherms, human physiology employs various body processes to maintain the central core temperature near 37oC (98.6oF). With a skin temperature around 33.9oC (93oF), the core-skin temperature differential is "optimal," and we generally feel neither hot nor cold -- a state we term "comfortable." (Please note our discussion here is general in nature and assumes a healthy human body. Individuals may vary widely in their responses to their thermal environment due to a large number of body factors.)

When heat cannot be lost quickly enough to maintain the body's ideal temperature differential, internal heat builds up and we feel "hot." The body's thermal regulators soon respond to increase our heat loss through increased perspiration, urination and desire for water, and decreased metabolism.

On the other side of the thermal regulatory continuum, when internal heat is lost too rapidly, we begin to feel "cold," and the body again reacts. This time, shivering, "goose flesh," decreased perspiration and increased metabolism are some of the main responses.

How we feel under prevailing environmental thermal conditions, therefore, is more a response to the rate of body heat gain or loss rather than to the absolute temperature. Thus, we may feel cool in the summer under temperatures considered balmy during winter.

Unlike other animals, humans have the short-term option of aiding the body in heat regulation by adding or removing clothing to maintain an overall comfort level. Thus, we rarely venture out into the cold outdoors naked. If we did, we would lose heat rapidly, and under extreme conditions could face death in a few hours of exposure.

How fast we lose heat depends primarily on the air temperature and the wind speed. (Exposure to full sun can counter some of the heat loss to cold temperatures and windy conditions, and being wet can increase heat loss through evaporation.) Under calm or near calm conditions, we lose heat faster as environmental temperatures become colder. But when the wind blows faster than a threshold speed, we begin to lose heat at a rate, much more rapid than the loss due to temperature differential alone.

...furthermore

This is utterly false. The wind speed, however strong, does not change the actual air temperature. If we placed two identical thermometers side-by-side, one exposed to the wind and the other sheltered, they will read the same unless other factors such as radiation or moisture on the sensor are affecting one of them.

Thus, no matter what the equivalent windchill temperature may be, the temperature of a living body (human or animal) or an inanimate object (e.g., a car radiator) exposed to the air will never drop below the actual air temperature unless wet (when evaporative cooling may lower the surface temperature). Therefore, exposed water or other liquids will not freeze unless the air temperature is below their freezing point.

I was curious if cold-blooded animals were affected the same way we were to windchill. They are, but they don't feel as bad as we do in the cold. We must maintain a higher temperature, so we feel more cold. If a snake and a human were side by side in any air temperature at any wind speed, both core temperatures would be the exact same, after they equalize with the surrounding air temp. Wind speed just hurries the process.

FYI for you all.

 

[Nyati13]

Originally posted by: edro
Windchill: a still-air temperature that would have the same cooling effect on exposed human skin as a given combination of temperature and wind speed.
From: http://www.islandnet.com/~see/weather/life/windchill.htm

As warm-blooded animals, or poikilotherms, human physiology employs various body processes to maintain the central core temperature near 37oC (98.6oF). With a skin temperature around 33.9oC (93oF), the core-skin temperature differential is "optimal," and we generally feel neither hot nor cold -- a state we term "comfortable." (Please note our discussion here is general in nature and assumes a healthy human body. Individuals may vary widely in their responses to their thermal environment due to a large number of body factors.)

When heat cannot be lost quickly enough to maintain the body's ideal temperature differential, internal heat builds up and we feel "hot." The body's thermal regulators soon respond to increase our heat loss through increased perspiration, urination and desire for water, and decreased metabolism.

On the other side of the thermal regulatory continuum, when internal heat is lost too rapidly, we begin to feel "cold," and the body again reacts. This time, shivering, "goose flesh," decreased perspiration and increased metabolism are some of the main responses.

How we feel under prevailing environmental thermal conditions, therefore, is more a response to the rate of body heat gain or loss rather than to the absolute temperature. Thus, we may feel cool in the summer under temperatures considered balmy during winter.

Unlike other animals, humans have the short-term option of aiding the body in heat regulation by adding or removing clothing to maintain an overall comfort level. Thus, we rarely venture out into the cold outdoors naked. If we did, we would lose heat rapidly, and under extreme conditions could face death in a few hours of exposure.

How fast we lose heat depends primarily on the air temperature and the wind speed. (Exposure to full sun can counter some of the heat loss to cold temperatures and windy conditions, and being wet can increase heat loss through evaporation.) Under calm or near calm conditions, we lose heat faster as environmental temperatures become colder. But when the wind blows faster than a threshold speed, we begin to lose heat at a rate, much more rapid than the loss due to temperature differential alone.

...furthermore

This is utterly false. The wind speed, however strong, does not change the actual air temperature. If we placed two identical thermometers side-by-side, one exposed to the wind and the other sheltered, they will read the same unless other factors such as radiation or moisture on the sensor are affecting one of them.

Thus, no matter what the equivalent windchill temperature may be, the temperature of a living body (human or animal) or an inanimate object (e.g., a car radiator) exposed to the air will never drop below the actual air temperature unless wet (when evaporative cooling may lower the surface temperature). Therefore, exposed water or other liquids will not freeze unless the air temperature is below their freezing point.

I was curious if cold-blooded animals were affected the same way we were to windchill. They are, but they don't feel as bad as we do in the cold. We must maintain a higher temperature, so we feel more cold. If a snake and a human were side by side in any air temperature at any wind speed, both core temperatures would be the exact same, after they equalize with the surrounding air temp. Wind speed just hurries the process.

FYI for you all.

Reptiles do not persperate (sweat) and so they are not effected by wind chill.

 

[dullard]

Originally posted by: edro
I was curious if cold-blooded animals were affected the same way we were to windchill. They are, but they don't feel as bad as we do in the cold. We must maintain a higher temperature, so we feel more cold. If a snake and a human were side by side in any air temperature at any wind speed, both core temperatures would be the exact same, after they equalize with the surrounding air temp. Wind speed just hurries the process.

Your understanding and thus this post is fundamentally flawed. We have four major factors to consider:
[*]Surrounding temperatures (hot 90°F day vs cold 50°C day, both are ~20°F from human's ideal temp).
[*]Surrounding air speed (calm ~0 mph winds vs blustery 40 mph winds).
[*]Body mass (small lizzard vs large human).
[*]Strength of energy source within the body (small for cold blooded vs large for warm blooded).

You appear to be addressing 2.5 of those issues and blur and confuse the rest.

Ultimately, reptiles at a cold temperature will become cold themselves and will be slow and sluggish. However, their body mass and air speed will affect how fast they reach that stage. A large reptile in a calm cold night will be warm/energetic for quite some time after the heat of the day is gone. A small reptile in a windy night will reach that cold temperature quickly.

So yes, they are affected by wind speed during the temperature transition.

And no, the core temperature of reptiles and humans WON'T be the same on a windy day or on a calm day unless the human is dead.

 

[Gibsons]

Originally posted by: dullard

Originally posted by: edro
I was curious if cold-blooded animals were affected the same way we were to windchill. They are, but they don't feel as bad as we do in the cold. We must maintain a higher temperature, so we feel more cold. If a snake and a human were side by side in any air temperature at any wind speed, both core temperatures would be the exact same, after they equalize with the surrounding air temp. Wind speed just hurries the process.

Your understanding and thus this post is fundamentally flawed. We have four major factors to consider:
[*]Surrounding temperatures (hot 90°F day vs cold 50°C day, both are ~20°F from human's ideal temp).
[*]Surrounding air speed (calm ~0 mph winds vs blustery 40 mph winds).
[*]Body mass (small lizzard vs large human).
[*]Strength of energy source within the body (small for cold blooded vs large for warm blooded).

You appear to be addressing 2.5 of those issues and blur and confuse the rest.

Ultimately, reptiles at a cold temperature will become cold themselves and will be slow and sluggish. However, their body mass and air speed will affect how fast they reach that stage. A large reptile in a calm cold night will be warm/energetic for quite some time after the heat of the day is gone. A small reptile in a windy night will reach that cold temperature quickly.

So yes, they are affected by wind speed during the temperature transition.

And no, the core temperature of reptiles and humans WON'T be the same on a windy day or on a calm day unless the human is dead.

Or if the temperature is about 98F.

 

[dullard]

Originally posted by: Gibsons
Or if the temperature is about 98F.

You got me there. I missed that exception. :thumbsup:

 

[edro]

Originally posted by: Nyati13

Originally posted by: edro
Windchill: a still-air temperature that would have the same cooling effect on exposed human skin as a given combination of temperature and wind speed.
From: http://www.islandnet.com/~see/weather/life/windchill.htm

As warm-blooded animals, or poikilotherms, human physiology employs various body processes to maintain the central core temperature near 37oC (98.6oF). With a skin temperature around 33.9oC (93oF), the core-skin temperature differential is "optimal," and we generally feel neither hot nor cold -- a state we term "comfortable." (Please note our discussion here is general in nature and assumes a healthy human body. Individuals may vary widely in their responses to their thermal environment due to a large number of body factors.)

When heat cannot be lost quickly enough to maintain the body's ideal temperature differential, internal heat builds up and we feel "hot." The body's thermal regulators soon respond to increase our heat loss through increased perspiration, urination and desire for water, and decreased metabolism.

On the other side of the thermal regulatory continuum, when internal heat is lost too rapidly, we begin to feel "cold," and the body again reacts. This time, shivering, "goose flesh," decreased perspiration and increased metabolism are some of the main responses.

How we feel under prevailing environmental thermal conditions, therefore, is more a response to the rate of body heat gain or loss rather than to the absolute temperature. Thus, we may feel cool in the summer under temperatures considered balmy during winter.

Unlike other animals, humans have the short-term option of aiding the body in heat regulation by adding or removing clothing to maintain an overall comfort level. Thus, we rarely venture out into the cold outdoors naked. If we did, we would lose heat rapidly, and under extreme conditions could face death in a few hours of exposure.

How fast we lose heat depends primarily on the air temperature and the wind speed. (Exposure to full sun can counter some of the heat loss to cold temperatures and windy conditions, and being wet can increase heat loss through evaporation.) Under calm or near calm conditions, we lose heat faster as environmental temperatures become colder. But when the wind blows faster than a threshold speed, we begin to lose heat at a rate, much more rapid than the loss due to temperature differential alone.

...furthermore

This is utterly false. The wind speed, however strong, does not change the actual air temperature. If we placed two identical thermometers side-by-side, one exposed to the wind and the other sheltered, they will read the same unless other factors such as radiation or moisture on the sensor are affecting one of them.

Thus, no matter what the equivalent windchill temperature may be, the temperature of a living body (human or animal) or an inanimate object (e.g., a car radiator) exposed to the air will never drop below the actual air temperature unless wet (when evaporative cooling may lower the surface temperature). Therefore, exposed water or other liquids will not freeze unless the air temperature is below their freezing point.

I was curious if cold-blooded animals were affected the same way we were to windchill. They are, but they don't feel as bad as we do in the cold. We must maintain a higher temperature, so we feel more cold. If a snake and a human were side by side in any air temperature at any wind speed, both core temperatures would be the exact same, after they equalize with the surrounding air temp. Wind speed just hurries the process.

FYI for you all.

Reptiles do not persperate (sweat) and so they are not effected by wind chill.

That chilling effect is due to evaporation, not wind chill.

 

[Nyati13]

Originally posted by: edro

Originally posted by: Nyati13

Reptiles do not persperate (sweat) and so they are not effected by wind chill.

That chilling effect is due to evaporation, not wind chill.

Right, and no sweat equals no evaporation equals no chilling effect equals no wind chill, which is exactly what I had said. Reptiles are not effected by wind chill.

 

[dullard]

Originally posted by: Nyati13
Right, and no sweat equals no evaporation equals no chilling effect equals no wind chill, which is exactly what I had said. Reptiles are not effected by wind chill.

The bolded part is false. A dry object will still heat/cool faster in moving air than in still air.

 

[manowar821]

Originally posted by: dullard

Originally posted by: Nyati13
Right, and no sweat equals no evaporation equals no chilling effect equals no wind chill, which is exactly what I had said. Reptiles are not effected by wind chill.

The bolded part is false. A dry object will still heat/cool faster in moving air than in still air.

LOL, picky picky.

 

[KMurphy]

Originally posted by: Nyati13

Originally posted by: edro

Originally posted by: Nyati13

Reptiles do not persperate (sweat) and so they are not effected by wind chill.

That chilling effect is due to evaporation, not wind chill.

Right, and no sweat equals no evaporation equals no chilling effect equals no wind chill, which is exactly what I had said. Reptiles are not effected by wind chill.

That is wrong. Moving air removes heat over a given surface area. How to you explain why today's processors require a fan to remove additional heat? From your example, the HS doesn't sweat so shouldn't be effected by additional air moving across it.

 

[VTHodge]

I think Dullard is pretty much right on.

The main factor in windchill is not evaporation it is convection. Convection is a heat transfer method where a fluid (liquid or gas) is based over a body (usually a solid). Convection is effective because the fluid (the wind) is not effected by your body temperature. The differential between your surface temp and the air temp is maintained.

This is essentially why a blanket keeps you warm. Your body warms up the air around you, which can't move away because it is trapped by the blanket. It doesn't "trap the heat" (let's ignore the radiant effects, shall we?). It traps the air, which your body heats.

Also, humidity plays a factor in windchill. Humid air has far more thermal capacity than dry air, and thus can transfer heat more efficiently. This effect is much greater with still air (conduction vs. convection).

 

[Nyati13]

Originally posted by: KMurphy

Originally posted by: Nyati13

Originally posted by: edro

Originally posted by: Nyati13

Reptiles do not persperate (sweat) and so they are not effected by wind chill.

That chilling effect is due to evaporation, not wind chill.

Right, and no sweat equals no evaporation equals no chilling effect equals no wind chill, which is exactly what I had said. Reptiles are not effected by wind chill.

That is wrong. Moving air removes heat over a given surface area. How to you explain why today's processors require a fan to remove additional heat? From your example, the HS doesn't sweat so shouldn't be effected by additional air moving across it.

Still air can take heat away also, it doesn't require moving air. But, it's right that moving air will cool more than still air, by steadily replacing the air around the warm body with fresh cooler air. Which is wind chill I guess ...

 

[Jeff7]

Originally posted by: edro

Originally posted by: Nyati13
Reptiles do not persperate (sweat) and so they are not effected by wind chill.

That chilling effect is due to evaporation, not wind chill.

CPU heatsinks benefit greatly from wind chill caused by the fan.


Take two reptiles (or even just heatsinks) of the same temperature, and place them in a room of a different temperature. The reptile in the room with better air circulation will reach the temperature of the air faster than the one in the still room. More air movement = better heat transfer.

But since the reptiles can't generate their own heat, they will no longer continue to lose energy to their surroundings once they reach equilibrium.

 

[WHAMPOM]

Windchill is pretty much a measure of how fast you lose heat.
30 degrees on the wind chill chart at whatever wind-speed equals the temperature you would experience heat loss.