Infrared heating and implants

I have a probably stupid question about infrared heating...

Recently I was looking at an apartment which has infrared heating installed in the ceiling. I know it's supposed to heat just the body and not air around it, thus being very efficient, but what about people with implants? I found one answer online:

"Metal and artificial joints or implants can heat up at a different rate than the body which is why the use of infrared heat is not recommended for those who have them. Clients who have metal or any other surgical implants in their bodies should consult their doctor prior to using heating devices." (source).

The answer is about using an infrared sauna, which probably creates higher temperature, but on the other hand, at home people are typically exposed to the heat source for longer.
I guess the apartment should be safe as many people have various body implants, especially the elderly, and infrared heating is becoming more popular... but I once experienced that the implant I have warmed up more than the rest of my body, when I was leaning against a radiator (the old fashioned one with hot water running through it). It happened only once but it was very unpleasant!

Thanks for sharing. Unfortunately, this makes sense.  I wonder about the time frame for the exposure to have an unpleasant impact….

John F Dean wrote:I wonder about the time frame for the exposure to have an unpleasant impact….

In my case, it was maybe 1-2 hours. It was an old house which was very cold and a friend was just moving in, so the house didn't have time to warm up much. I was sitting against that radiator talking to her and didn't realize that I'm starting to roast myself ;)

With infrared heating in the ceiling, when the house is already warm (heating working daily) I guess the body will be able to spread the temperature around, during daily activity... I would worry about the nighttime, as people aren't moving that much during sleep.

Also, wouldn't it be the same with metal jewelry? One can always take it off but still creepy if you suddenly realize that your necklace is getting hot :)) or warmer than the body anyway. Or colder? I haven't found much about house heating.

Don’t worry. This is *not* like a microwave oven where metal will absorb so much heat that you can’t or shouldn’t put metal in a microwave. It’s not like that. Infrared heating is basically the same as heat from a woodstove, or heating from sunshine. And yes, metal left in the sun could get hot, but even a single thin layer of fabric/clothing would prevent that I think.

Making physical contact is a different kind of heat transfer called “conduction”.  It is often much faster at transferring heat, especially with metal since metal has high thermal conductivity.   This is why before touching hot metal on a stove we use something insulating in-between like a pot holder, mitt or glove.  

Thanks Mike! That makes sense, and explains the difference between infrared house heating and saunas... would be silly if people cooked themselves in this kind of apartments :))