heat pads

Re: heat pads

Anthony Todd — Mon, 08 Feb 2010 23:30:41 GMT

"Heat or thermal burns occur when the skin touches a hot surface. The skin may either be in contact with hot liquids, flames, steam, flash, or extremely hot surfaces. The minimum temperature that could cause heat burns is 115º F. This can occur anywhere at home like exposure to irons, stoves, hot kettles, and others."

"They use common design parameters that are centered around the surface temperature of any material not exceeding 120° F (° 50°C) because this provides a contact exposure limit of eight minutes before 2nd degree burns are probable, and 3rd degree burns can be expected in ten minutes."

Minimum temperature to cause burns 44°C for 5 to 6hours 65°C-2sec.

Three pulls from google, the 44 degrees surprised me.

Have tested, with a remote sensor, three mains powered under animal pads and they wouldn't go above 42.8 but a microwavable corn bag, heated as instructed, got to 48.

Of course once the towel or whatever gets wet you get direct heat conduction.

Everyone take care!

Re: heat pads

salome2001 — Mon, 08 Feb 2010 22:25:56 GMT

slightly off topic, but I've seen a staffy with second degree burns on the back from sitting against the radiator at home. Owners quite upfront about the aetiology: they usually stop the dog doing it but went out for the evening and the babysitter didn't... The dog was a typically brainless and very accident prone example of its breed so it didn't surprise me... (but a very nice dog otherwise)

Re: heat pads

salome2001 — Mon, 08 Feb 2010 22:22:03 GMT

Maybe I've been lucky, but I've only ever used green heat pads with at least one layer of vetbed and that seems to provide adequate insulation to protect from burns

Re: heat pads

Tom Lonsdale — Sun, 31 Jan 2010 01:33:18 GMT

Hi Tony,

Back in the 70s I was aware of my good luck working alongside you and Malcolm Corner. Passage of time only confirms that view. Do you remember how a high profile eye vet advised you under no circumstances to hire me?

Urine, blood and faeces can all turn a convected heat source into a conducted heat source with adverse effects. On occasion have grabbed oven mits and only in use realised they were damp/wet. Ouch.

Yea, plenty of sanctimonious talk about cat gut. Best not to get drawn in. Reserve all indignation for the mass poisoning of pets, I say. Hope you’ll vote for me (actually not for me but the cause) in the forthcoming RCVS elections.

Have fun,

Tom

Re: heat pads

Anthony Todd — Fri, 29 Jan 2010 23:12:21 GMT

Hi Tom,

Thank you for the total exaggeration although "tricks" might be allowed, just, in your opening.

Agree with the wet heat theory. Water is a great conductor of heat which is why you boil eggs in it. And a hot water bottle is the same as hot hands in effect.

Still can't get another heat pad above 43 so i'm going to use them solely in future to thermalise all those bitch spay breakdowns from cat gut we used to get, so negligent don't you think......

best wishes,

Re: heat pads

Jillian Hall — Wed, 27 Jan 2010 21:34:29 GMT

I've also seen cats popping a claw through "hot hands" so that they spring a leak. The resultant soggy cats get very cold very quickly.

Re: heat pads

Tom Lonsdale — Tue, 26 Jan 2010 23:17:55 GMT

G'day Tony,

Yeah, I learned so many tricks of the trade at the feet of you the master in the mid-seventies. However, some I had to learn the hard way on my own.

The one case of thermal burns that stands out in the memory was back in the early eighties as I was beginning to get established in Sydney.

Propped the little Min Foxie spay between hot water bottles as had done on so many cases before. When the Min Foxie presented with skin necrosis some couple of weeks later, the owner thought the skin had been damaged possibly when the dog slipped under a fence.

I kept mum on that, because to me it looked like skin prep solution had pooled and created 'wet heat' in a specific area.

Thereafter, thick blanket was placed between the skinny/little patients and their heat source and as I recall no more 'scalds' were seen.

Things is always a matter of degree, however don't know if the rule can be reduced to 'dry heat good: wet heat bad' but it might be worth investigating.

Good to chat again.

Cheers,

Tom

Re: heat pads

Anthony Todd — Tue, 26 Jan 2010 22:28:29 GMT

Operating Temperature

High: 43° ± 3°C (109.4° ± 5.4° F)
Med: 38° ± 3°C (100.4° ± 5.4° F)
Low: 32° ± 3°C (89.6° ± 5.4° F)

From the Bair website which would suggest what i have said may be in the ballpark??

Re: heat pads

Anthony Todd — Tue, 26 Jan 2010 22:21:13 GMT

Er, without wanting to make any comments,comparisons or implications regarding mass and/or surface area of the example quoted by Ms. Dunnett [;-)] my observations showed that the pad measured didn't get above 42 degrees odd and didn't seem to increase with increased weight..

Does this mean that 42C will cause a burn?? I realise that a burn is a function of temperature multiplied by time [hold your finger in a candle flame] but 42 seems below the burn threshold??

We certainly had one burn where a microwaved heating pad was involved and these are now banned.

Is there any substantive evidence that anything other than very gradual warming using a heat source very little higher than normal body temp is desireable?

How hot is the Bair air??

Re: heat pads

jd2008 — Tue, 26 Jan 2010 18:34:16 GMT

Hi! We've unfortunately had thermal burns in the past from table-top heating pads though only in heavy dogs - I tried it out on myself by sitting on it for half an hour (slow afternoon!) and found it uncomfortably hot even through clothing. Have seen a couple from microwavable heat pads/wheat bags too over the years and we now have strict policies in place regarding their use. Basically we never use under-animal heating sources on an unconscious or immobile animal.

We use Bair huggers (picked up a couple cheaply at auction) and they really are the mutts nuts. Don't necessarily need to use the special blankets either - they tend to puncture very easily. It works just as well by sticking the pipe under a foil blanket +/- towel or vet bed wrapped round the patient.

Have never been too keen on hot-hands as they tend to get forgotten, become cold then work in reverse drawing heat away from the patient.

Other things that look like thermal burns? Direct burn from hot water/caustic agent, skin slough from s.c fluids or severe reaction to s.c medication?

Jane