Interesting article about temperature regulation in horses. Worth a read

Last week when mine were still out at night someone commented that they came up to the yard one evening and there was a row of stabled chunky irish horses all with rugs and there were my two tbs out in the fields naked. One of them who's a real wimp had a rain sheet one night when it was raining heavily but that's it. They swapped to day turnout this weekend and apart from one other horse on the yard, they are the only ones who are rugless day and night.
 
ycbm said:
The stuff about stone stables versus wood is absolute rubbish. Horses do not radiate heat to the nearest available solid surface. They radiate heat into the air that surrounds them. The amount of heat that they lose is dependant on the air temperature, not the temperature of the walls.

In addition, in winter, daylight temperatures (especially if it's sunny) will heat up stone walls, which then release that heat when the temperature drops at night, meaning that the air in stone stables is often noticeably warmer than the air in wooden stables, which lose their heat much quicker because an inch or two of wood is much less insulating than 8 inches of concrete block.

For the same reason, the greater insulation of stone walls, the heat of the horse inside the stable is better retained, and unless you have big draughts or a very high ceiling, a stone stable will be warmer than a wooden one in very cold weather.
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Unless you have rewritten the laws of thermodynamics (?), it's not "absolute rubbish". Not even partial rubbish. The transfer of radiant heat occurs between adjacent bodies or surfaces without the need for direct contact and without convection. In the case of the Sun and radiant heat transfer, the Sun is the hotter body and transmits radiation to us (the cooler body), warming us. In a stone building, we are the radiant body (the equivalent of the Sun) as we are hotter and we radiate heat to the colder walls. Its all very clearly explained here: https://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
 
Second Law of Thermodynamics: Heat, cannot of itself pass, from one body to a hotter body.

Great article, David. Thank you. Have shared across SM. Of course there is always one who strongly believes their horse breaks all the rules... one day the message will get through.
 
I have to say mine does actually break the rules and trying to rug her as I would a normal horse of her size and type (i.e. she's enormous and hairy and shouldn't need a rug at all unless it goes below freezing with added windchill and rain) has resulted in a tye up again. (I've done a slightly drunken rambling thread about it if anyone is interested). I hate it because I hate over-rugging and my elderly Anglo Arab is often the least rugged up horse on a yard and people think I'm cruel but she's fine. But then the big fat cob that needs rugging to the eyeballs comes along and I can't process it. And other people go "see, we told you they needed rugs".... at least they do in my imagination.
 
Dr David Marlin said:
Unless you have rewritten the laws of thermodynamics (?), it's not "absolute rubbish". Not even partial rubbish. The transfer of radiant heat occurs between adjacent bodies or surfaces without the need for direct contact and without convection. In the case of the Sun and radiant heat transfer, the Sun is the hotter body and transmits radiation to us (the cooler body), warming us. In a stone building, we are the radiant body (the equivalent of the Sun) as we are hotter and we radiate heat to the colder walls. Its all very clearly explained here: https://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
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I think it is possibly a little confusing where you say that the walls 'draw' heat out of a horse, which isn't really true, it's just that cooler objects radiate less heat back, so the net is more. But the amount of heat that is radiated by a horse is dependent on its own temperature, size and shape (and whether it is wearing a rug)
 
I hesitate to contradict a professor but aren't we just talking different laws of physics as opposed to one being wrong and the other right: stone buildings have a large thermal mass and will stay warmer than the outside air once the temps have dropped.

I checked this all out with my OH who is a Physicist - this is his day job - and he's with ycbm on this one!

According to him the article linked to is all totally accurate but does not really apply to the situation of a horse in a stable, Radiant heat generally becomes significant when we are talking about white hot bodies. Like the sun! So yes horses are the 'radiant body' but radiant heat loss from a horse is negligible compared to heat loss by convection. Not even radiators 'radiate'. Horses will lose heat rapidly once temperatures drop around them as they seek to reach thermal equilibrium with their surroundings. The vast majority of that heat loss will be via convection. As a stone stable has a larger thermal mass than a wooden one it will stay warmer anbd so will the horse.
 
Ambers Echo said:
I have endless arguments with my daughters about over-rugging. We have found a compromise that means they are probably rugged a little more than they need to be but not enough for them to overheat. Plus they stay cleaner that way which is useful for competition ponies who live out 24/7.
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I must say that I wouldn't argue with children about over-rugging, I would simply tell them how it is going to be. Perhaps now that there has been an incident with one of the ponies expressing her dislike of rugging would be a good time to insist on pony welfare over a child's natural inclination to 'dress up'. Especially as that pony isn't going to be competing in the near future.
This might be a good opportunity for the children to really understand how ponies keep themselves warm.
 
Dr David Marlin said:
Unless you have rewritten the laws of thermodynamics (?), it's not "absolute rubbish". Not even partial rubbish. The transfer of radiant heat occurs between adjacent bodies or surfaces without the need for direct contact and without convection. In the case of the Sun and radiant heat transfer, the Sun is the hotter body and transmits radiation to us (the cooler body), warming us. In a stone building, we are the radiant body (the equivalent of the Sun) as we are hotter and we radiate heat to the colder walls. Its all very clearly explained here: https://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
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David, a horse is not a fusion reactor. Horses lose heat into the surrounding air. The amount of heat a horse loses is unaffected by any surface that is around that at air. The fact that a wall itself is warm or cold does not alter the amount of heat lost by the horse, only the air temperature.

I live in a stone building with walls two feet thick. So do my horses. They air inside them is cooler in summer and warmer in winter than wood ones, and I rug accordingly.

If you are going to go all physics on us, you really do need to include the heating effect of the horse on the air around it and the difference in insulation properties of wood and stone to keep that heat inside the stable with the horse, and the thermal inertia which means thick stone walls release heat into cooler air and cool hotter air much more effectively than a thin piece of wood.

You spoiled a really good argument with nonsense physics which isn't right in terms of horse rugging, and are making it worse by arguing about it.
 
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I’m not sure this argument about physics is very relevant to the thread 🙄

I currently have one rigged and three not. Another will have a rug if it rains but the other two will stay rugless. The rugless ones will also have a belly clip. They are all natives but are all different, including their coats. One of tbe unrugged ones gets too hot in a stable but the other one feels chilly. The hot one is quite big for his (wooden) stable so less air around him.

I’d always say start with the minimum and only rug/add extra If it’s obvious you need to. Modern rugs are very good at being effective over a wider range of temperatures so adding rugs when it gets colder isn’t always necessary. I would never want mine shivering, but the odd occasion if the weather has changed suddenly won’t hurt them!
 
Pearlsasinger said:
I must say that I wouldn't argue with children about over-rugging, I would simply tell them how it is going to be. Perhaps now that there has been an incident with one of the ponies expressing her dislike of rugging would be a good time to insist on pony welfare over a child's natural inclination to 'dress up'. Especially as that pony isn't going to be competing in the near future.
This might be a good opportunity for the children to really understand how ponies keep themselves warm.
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You raise an interesting point about kids and ponies: how to balance educating them with allowing or expecting them to be indepdendently responsible for their own ponies which includes making those sorts of decisions - and at their age (14) even allowing them to just disagree with me! Where there is a clear welfare issue of course I step in. But this isn't that - it's rugging a little more then the horse might strictly need and a lot less than everyone else rugs! It is not a welfare issue in my view. I doubt the rug was a trigger for Ginny but it is a point worth considering so thank-you for that suggestion. But when she first arrived she would lunge at people in the same way if they were brining her hay or just being near her in her stable and rugging her when she is tied up on the yard which we have gone back to doing is not causing any problems.

We are havimng a similar dilemma about barefoot. Jenny's shoes are off and Izzy wants them back on as people are telling her ponies need shoes. At the moment I am winning that one!
 
On a slightly different note, at pony club camp in spring all the campers were told their ponies needed rugs in their stables at night! (The same pony club that peddles the myth about scraping after hosing to avoid super-heating the ponies). How do I combat the over-rugging mind-set when up against that kind of rubbish? Is there any kind of curriculum that PC teaches to? And if so who oversees it/updates it because I really object to my kids being taught things that are at best just unnecessary and at worst may lead to mismanagement like over-rugging.
 
Ah! I hadn't realised that your girls are so old and I do appreciate that it is difficult on a livery yard where other people do things differently (even if they are incorrect). I used to have a TBxWelsh mare who, when we first got her, was very proud of her food, especially around people, and also objected to rugging, girthing. We found, eventually, that she was in pain and when we got that sorted out she had the sweetest temperament ever. I'm glad that you are able to manage Ginny so that you are all safe during her rehab.
As for the shoes, I guess you pay the bills!
 
Ambers Echo said:
On a slightly different note, at pony club camp in spring all the campers were told their ponies needed rugs in their stables at night! (The same pony club that peddles the myth about scraping after hosing to avoid super-heating the ponies). How do I combat the over-rugging mind-set when up against that kind of rubbish? Is there any kind of curriculum that PC teaches to? And if so who oversees it/updates it because I really object to my kids being taught things that are at best just unnecessary and at worst may lead to mismanagement like over-rugging.
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I don't understand how this over-rugging myth has arisen in 'official' circles. I understand the power of marketting, especially over teenage or novice owners but I was taught as a child by 'old school' instructors that unclipped equines keep themselves warm so long as they are fed appropriately and have shelter in the worst weather and would have expected that knowledge and attitude to have been passed down to up-coming instructors. Weird isn't it?

Of course in those days, New Zealand rugs were not particularly attractive and were heavy to put on, so we weren't desperate to dress ponies up in them!
 
I'm afraid some posters in this thread are not understanding the laws of physics. All surfaces radiate heat - the amount of heat they radiate varies with the 4th power of the temperature measured in a scale called Kelvin. This is the Stefan-Boltzmann law of black body radiation. Those who want some gory details will find them here https://en.wikipedia.org/wiki/Stefan–Boltzmann_law. A horse will lose heat during the winter - the horse is warmer than the walls of its stable so the horse radiates more heat than the walls - there is a transfer of radiant heat. This has nothing to do with air temperature and everything to do with the surface temperature of the stable walls and the surface temperature of the horse.

Radiant heat is the same reason it gets cold on a clear night. The earth is warmer than deep space so it loses heat at night by radiation. The sun is warmer than the earth so the earth gains heat during the day. Desserts are the classic example - very very hot during the day and quite cold at night. Camels are exceptionally well adapted to cope with this temperature swing.

Is radiation the only source of heat loss? Of course not. Heat is transferred by convection to the surrounding air so a low air temperature will cool a horse. Heat is lost by evaporation (which is why we sweat), drinking cold water and even conduction. Conduction is when a hot body is in contact with a cold one.Metal feels cold in winter because it has high conduction so there is a high transfer of heat.

All these things make us unreliable thermometers - how cold we feel is not a reliable way of knowing the temperature. If I was to go outside on a wet winter day with only a thin shirt I will feel very very cold. The same air temperature on a still day when I am exercising will leave me feeling comfortable. The temperature is the same in both cases. 'windchill' is the term often used to describe how we perceive temperature compared to the actual temperature.

The science of heat is a complex subject and is one of the great scientific accomplishments of the 19th century physics.

Sorry for the physics lesson. I like to ask which came first - the horse, stable or rug?
 
DabDab said:
He's possibly not explaining very well, but is talking about thermal radiation/thermal infared, rather than heat transfer through convection or conduction. It passes from one body to another no matter the surrounding air temperature.

But of course this has very little impact when the air temperature is cold and therefore the greater thermal insulation properties mean that the heat that has been transferred from horse to walls does not then disappear instantly out into the outside air. Breeze blocks hold the temperature in, even if they can't heat transfer back in the horse's direction due to their emissivity. If that makes sense?
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I do specifically refer to radiation as opossed to convection or conduction to be fair! :)
 
Hack4fun said:
I'm afraid some posters in this thread are not understanding the laws of physics. All surfaces radiate heat - the amount of heat they radiate varies with the 4th power of the temperature measured in a scale called Kelvin. This is the Stefan-Boltzmann law of black body radiation. Those who want some gory details will find them here https://en.wikipedia.org/wiki/Stefan–Boltzmann_law. A horse will lose heat during the winter - the horse is warmer than the walls of its stable so the horse radiates more heat than the walls - there is a transfer of radiant heat. This has nothing to do with air temperature and everything to do with the surface temperature of the stable walls and the surface temperature of the horse.

Radiant heat is the same reason it gets cold on a clear night. The earth is warmer than deep space so it loses heat at night by radiation. The sun is warmer than the earth so the earth gains heat during the day. Desserts are the classic example - very very hot during the day and quite cold at night. Camels are exceptionally well adapted to cope with this temperature swing.

Is radiation the only source of heat loss? Of course not. Heat is transferred by convection to the surrounding air so a low air temperature will cool a horse. Heat is lost by evaporation (which is why we sweat), drinking cold water and even conduction. Conduction is when a hot body is in contact with a cold one.Metal feels cold in winter because it has high conduction so there is a high transfer of heat.

All these things make us unreliable thermometers - how cold we feel is not a reliable way of knowing the temperature. If I was to go outside on a wet winter day with only a thin shirt I will feel very very cold. The same air temperature on a still day when I am exercising will leave me feeling comfortable. The temperature is the same in both cases. 'windchill' is the term often used to describe how we perceive temperature compared to the actual temperature.

The science of heat is a complex subject and is one of the great scientific accomplishments of the 19th century physics.

Sorry for the physics lesson. I like to ask which came first - the horse, stable or rug?
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Thank you :) The Dunning-Kruger effect is clearly alive and kicking on H&H Forum ;)
 
Hack4fun said:
I'm afraid some posters in this thread are not understanding the laws of physics. All surfaces radiate heat - the amount of heat they radiate varies with the 4th power of the temperature measured in a scale called Kelvin. This is the Stefan-Boltzmann law of black body radiation. Those who want some gory details will find them here https://en.wikipedia.org/wiki/Stefan–Boltzmann_law. A horse will lose heat during the winter - the horse is warmer than the walls of its stable so the horse radiates more heat than the walls - there is a transfer of radiant heat. This has nothing to do with air temperature and everything to do with the surface temperature of the stable walls and the surface temperature of the horse.

Radiant heat is the same reason it gets cold on a clear night. The earth is warmer than deep space so it loses heat at night by radiation. The sun is warmer than the earth so the earth gains heat during the day. Desserts are the classic example - very very hot during the day and quite cold at night. Camels are exceptionally well adapted to cope with this temperature swing.

Is radiation the only source of heat loss? Of course not. Heat is transferred by convection to the surrounding air so a low air temperature will cool a horse. Heat is lost by evaporation (which is why we sweat), drinking cold water and even conduction. Conduction is when a hot body is in contact with a cold one.Metal feels cold in winter because it has high conduction so there is a high transfer of heat.

All these things make us unreliable thermometers - how cold we feel is not a reliable way of knowing the temperature. If I was to go outside on a wet winter day with only a thin shirt I will feel very very cold. The same air temperature on a still day when I am exercising will leave me feeling comfortable. The temperature is the same in both cases. 'windchill' is the term often used to describe how we perceive temperature compared to the actual temperature.

The science of heat is a complex subject and is one of the great scientific accomplishments of the 19th century physics.

Sorry for the physics lesson. I like to ask which came first - the horse, stable or rug?
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The horse is not a planet or a fusion reactor producing unimaginable amounts of heat.

The horse is a living being which creates body heat. It does not spend all day sucking up heat from the sun and then releasing it when the sun is down. It creates heat constantly, and that heat is dispersed into the air constantly irrespective of what temperature the walls are surrounding the air the horse is stood in. Any horse does not radiate any more heat if a wall is cold or hot. It radiates the amount of heat necessary to keep its core body temperature stable. And that depends only on how much heat it is losing into the air.

The argument fails even before you add the relative insulating properties of thick stone and thin wood, and the ability of a stone wall to collect heat from the sun during the day and radiate it out overnight, where the radiating really does count, like in a storage radiator (which has a block of stone in it to do exactly that).

In terms of advice about rugging, this matters. Stone walls feel colder than wood ones even at the same temperature. People are, in general, already rugging too much. They do not need advice that their horse is likely to be colder if it is in a stone stable. It's quite simply advice that should be reversed.
 
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ycbm said:
David, a horse is not a fusion reactor. Horses lose heat into the surrounding air. The amount of heat a horse loses is unaffected by any surface that is around that at air. The fact that a wall itself is warm or cold does not alter the amount of heat lost by the horse, only the air temperature.

I live in a stone building with walls two feet thick. So do my horses. They air inside them is cooler in summer and warmer in winter than wood ones, and I rug accordingly.

If you are going to go all physics on us, you really do need to include the heating effect of the horse on the air around it and the difference in insulation properties of wood and stone to keep that heat inside the stable with the horse, and the thermal inertia which means thick stone walls release heat into cooler air and cool hotter air much more effectively than a thin piece of wood.

You spoiled a really good argument with nonsense physics which isn't right in terms of horse rugging, and are making it worse by arguing about it.
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You could not be more wrong :) Have a read of some of the other comments by people who understand physics. :) Have a look at the Dunning-Kruger principle ;)
 
ycbm said:
David, a horse is not a fusion reactor. Horses lose heat into the surrounding air. The amount of heat a horse loses is unaffected by any surface that is around that at air. The fact that a wall itself is warm or cold does not alter the amount of heat lost by the horse, only the air temperature.

I live in a stone building with walls two feet thick. So do my horses. They air inside them is cooler in summer and warmer in winter than wood ones, and I rug accordingly.

If you are going to go all physics on us, you really do need to include the heating effect of the horse on the air around it and the difference in insulation properties of wood and stone to keep that heat inside the stable with the horse, and the thermal inertia which means thick stone walls release heat into cooler air and cool hotter air much more effectively than a thin piece of wood.

You spoiled a really good argument with nonsense physics which isn't right in terms of horse rugging, and are making it worse by arguing about it.
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Why not come on my Facebook page @DrDavidMArlin and debate your views? You may find its a little uncomfortable though as there are some very bright and knowledgeable people on there :)
 
Dr David Marlin said:
Apparently, I have "spoilt" the thread by discussing science, at least according to YCBM.

Is this the view of most people?
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It hasn't spoilt the thread for me at all but I had already seen the post as I follow your FB page. I refuse to over rug and my two ponies (a Connie and a WB) are out at night, naked and will stay that way until it either pours with rain or they are clipped. Both are starting to sport lovely winter coats which in the mornings is standing up trapping the heat around them as nature intended.
 
Horses are a thermochemical reactor. They produce heat from chemical reactions.

There is a phenomena that could be called thermal inertia - it is how storage heaters work. Thick walls take longer to warm up than thin ones because they have greater heat capacity. In the same way they take longer to cool down. That's why your house may feel cool on a hot summer's day - it has not had enough time to reach thermal equilibrium. That won't be the case in protracted hot or cold spells. A thermometer is needed to measure the temperature. If the top half of the stable door is open, then air movement will have a major impact on air temperature and that will impact on the temperature of the surface of the stable walls. It is this surface temperature that determines radiative properties, not the bulk temperature.

There is also heat conduction through walls, and to the floor, and heat is transported through air movements. The mathematics of heat transfer are surprisingly fierce.

A simple thought experiment shows that heat transfer is influenced by the temperature of surfaces surrounding air. If it was only air temperature, an electric grill or toaster could not work. One could stand next to a whole wall of electric heaters - the type with a hot bar - and not be burnt.

Heat transfer is complex. Our perceptions of temperature are not a reliable way to assess heat gain or loss, and thermoregulation and heat transfer involving horses is completely different from people.
 
KautoStar1 said:
No. Don't worry she could start a row in an empty room. And instead of accepting she is wrong and has misunderstood she just keeps digging the hole and throwing herself in.
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In fact, I'm beginning to feel a sense of deja vu. Haven't we been here before? Or perhaps it was a different expert who didn't know as much as ycbm/google?
 
KautoStar1 said:
No. Don't worry she could start a row in an empty room. And instead of accepting she is wrong and has misunderstood she just keeps digging the hole and throwing herself in.
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I does amuse me. Start arguing with the science by using science, then when she feels she is losing the argument, start saying that science is spoiling it - fairly transparent behaviour!
 
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