How Does Cremation Work? +35 Weird Questions About Cremation

Sometimes the questions we have (especially questions about the cremation process) can be a bit weird, but we still need to ask them.

Thankfully, we have the internet!

You probably have a bunch of odd, quirky questions about cremation, and that’s completely normal.

How does cremation work?

Do bodies sit up during cremation?

What happens to the teeth, internal organs, casket?

Do dead bodies scream during cremation?

Is there a smell?

We all wonder about this stuff!

But maybe you don’t want to ask the funeral director, or you’re embarrassed to ask in front of your family. Or maybe the thought just occurred to you as you’re scrolling through your phone, waiting in line, or watching Netflix.

Whatever the case, we’re here to answer those common—but sometimes bizarre—cremation questions, as well as to give you some insight into how things work.

The Cremation Process: How Does Cremation Work?

The purpose of cremation is to reduce the body’s organic elements to ash and bone by use of fire and an industrial furnace.

For simplicity’s sake, we’ve laid out the entire procedure and process of cremation for you here, step by step:

  1. The first step and most important step in the entire cremation process is identification of the deceased. Cremation authorization documents are also double-checked. 
  2. The body placed in the retort, the crematory chamber of the large furnace where cremation is to occur. If the body is in a non-metal casket or cremation container, that will also go into the cremation furnace.
  3. Cremation begins. Depending on various factors of the body itself (such as weight), the process usually takes 2-3 hours. 
  4. The remains are removed from the retort and allowed time to cool down. At this point, all that is left is skeletal remains. Any non-consumed metal items (such as silver crowns, dental gold, or other dental work) are removed from the remains.
  5. Processing remains into ashes. The remaining bone fragments are then pulverized into small particles, which are commonly called cremation “ashes.”
  6. The ashes are respectfully transferred into a sturdy plastic bag, along with the metal tag, and then placed in their temporary container or permanent urn.
  7. The next-of-kin is notified that cremation is complete.

We’ll cover these steps in more detail below so — read on!

But first, here are some links to resources about cremation and cremation urns:

35 Questions About How Cremation Works

Here is everything you ever wanted to know—and probably some things you didn’t want to know—about the cremation process for humans.

1. What really happens when you are cremated?

The funeral director or crematorium operator would prepare the body, placing it in a wooden cremation casket or an alternative container. As an affordable option, you can choose a rigid cardboard container that is essentially a simple casket-shaped box with a lid.  

The retort (also called the cremation chamber) will then be turned on and allowed to reach an intense heat of 1400 to 1800 degrees. Once optimum temperature is reached, the body is placed into the chamber and the door is closed.

As the cremation takes place, the tissue and organs from the human remains will be completely incinerated by the very high temperatures within the chamber. All that will be left is bone material.

After the retort cools, the remaining ashes and bone fragments are collected, pulverized into a fine powder, placed in a temporary urn, and then returned to the deceased’s family.

2. Are the ashes really the person?

The ashes or cremains are actually bits of bone. So, yes, it really is the person. And it really is your family member or loved one.

Every crematorium has standard practice safety and identification protocols in place to make sure that each body (prior to cremation) and the cremated remains (after) are always 100% correct.

Firstly, the crematory operator will carefully check that all documents match the decedent’s ID.

In addition, a metal tag bearing an ID number — associated only with that particular decedent — will accompany the decedent into the retort. This provides another layer of ID security.

Lastly, the operator will also double-check cremation authorization documents and compare them to any other relevant documents to ensure proper identification.

You can rest assured that the ashes you receive will be the ashes of your loved one.

Related: Is There Energy In Cremated Ashes?

3. How common is cremation?

According to the National Funeral Director’s Association, the current rate of cremation is projected to be 57% versus 37% for traditional burial.

Cremation is more common in people’s final arrangements, too.

According to this report by the insurance firm Choice Mutual, 44% of Americans are planning on traditional cremation, versus 35% who plan on traditional burial. The remaining 21% are divided between don’t know or don’t care (10%), donate body to science (6%), natural burial (4%), and “other” (1%).

In short, it is safe to say that cremation is the most common disposition method in the country.

4. How soon after a funeral is a body cremated?

Cremations are scheduled to take place as soon after the funeral as possible. The cremation will usually take place the same day as the funeral.

Related: What is the Cremation Timeline?

5. How long does it take to cremate a body?

There are two questions here. First, How long does cremation take? Second, How long will it take for the ashes to get back to the family? It can vary from location to location.

From the time the crematory takes custody of the decedent, to the time the ashes are back with the family, can take anywhere from a few days to a week or longer. It’s a good idea to speak with the funeral director to get a better idea of what to expect.

Here are some of the factors affecting how long it will take for the ashes to get back to the family.

Legal Approval: 2-5 Days

There are some important legal steps that need to be taken before the cremation process can begin. These will vary by country, state, and even county or city.

Generally, the doctor has up to about 72 hours (3 days) to sign the death certificate. After that, the medical examiner may have up to 48 hours (2 days) to approve the cremation. Again, these matters will vary depending on the region, local regulations, and the schedules for the various offices involved. Talk with your local funeral director for more specific details.

Cremation: 2-3 hours

The crematory operator will consider the height and weight of the decedent as well as the temperature of the retort, which can reach up to 2000 degrees Fahrenheit. Because fat burns faster than other tissues, the crematory operator will consider the decedent’s fat-to-muscle ratio when determining how long the process will take.

Cooling: 1-2 hours

After the cremation, the retort holding remaining bone matter will need to be cooled for up to about 2 hours.

Processing the Remains: 1-2 hours

The final step is to get the remains from the retort, run a magnet over them (to pull out metal, for instance fillings or medical pins), pulverize the bone fragments into powder or “ashes,” then secure the remains into a container.

6. Can you be cremated without a funeral service?

Yes, you can be cremated without a funeral service. A cremation without a funeral service is called a direct cremation.

You can organize funeral arrangements or a memorial service at a later date (with the cremated remains present), or not at all. 

7. What is the cheapest way to be cremated?

whole-body donation includes a cremation at no cost. If donating your body to science is not for you, direct cremation is the least expensive.

Related: How Much Does Cremation Cost? (& Other Funeral Expenses)

8. Are bodies removed from the casket before cremation?

The body will be removed from the casket if the casket is not suitable for cremation. The casket will be cremated with the body if it is suitable.

Suitable caskets include eco-friendly natural woven caskets, all-wood caskets (no metal components), and a type of container made of heavy cardboard. Non-suitable caskets include anything with metal.

9. Do caskets get reused?

All rental caskets do get reused. A rental casket is what the funeral home will use for a traditional funeral service followed by cremation.

The body never touches the inside of the rental casket. The casket has a new insert for each body. The end of the casket opens, and the insert slides out. The insert is cremated with the body.

It is against the law to reuse a traditional casket.

10. How many bodies are cremated at once?

Cremating one body at a time is the law.

11. Do you have clothes on when you are cremated?

Have you opted for a direct cremation? If that is the case, you will be cremated in what you died in. Supposing you died naked, with a direct cremation you would be cremated naked.

But most families opt for the more traditional viewing, funeral service, and then cremation. If so, you will be cremated in the clothes that you were viewed in. 

12. What happens to jewelry during cremation?

This is another question where the answer lies with the wishes of the family. A decedent can wear jewelry during cremation. The operator will simply withdraw any jewelry remains with the ashes once cremation is over.

That said, the original states of any metal or stones will probably no longer exist due to the immense heat.

13. Does the body feel pain during cremation?

A body is already deceased when cremated. Pain cannot be felt because there are no nerve impulses.

14. Do bodies sit up during cremation?

No, bodies do not sit up. During to the cremation process, a body may go into a “pugilistic stance.”

The pugilistic stance is the post-mortem, “boxer-like” body posture of flexed elbows and knees and clenched fists, and is caused by the dehydration and shrinkage of body tissues and muscles. The body dehydration is initiated by the extremely high-temperatures in the cremation furnace.

While this may give a slight indication of movement or change from the traditional flat posture, it is a far cry from “sitting up.”

15. Do teeth burn in cremation?

Teeth usually burn up during cremation. Any tooth fragments that may be left are ground up with the bone fragments during the processing of the cremated remains.

16. Does the skull burst during cremation?

The skull does not burst during cremation. The skull will become fragile and crumble. This can give the illusion of bursting. 

17. Does a body get drained before cremation?

Draining a body of fluids does not happen before cremation.

If a body is embalmed before cremation, the bodily fluids are exchanged (drained, and then replaced) with chemicals during the embalming process. These chemicals are also fluid, but the body is not drained prior to cremation, whether or not an embalming has taken place.

Both embalmed and non-embalmed bodies can be cremated.

18. Are organs removed before cremation?

 Removing organs before cremation does not happen. Even if an autopsy has been performed, the organs are cremated with the rest of the body. 

19. Which part of the body does not burn during cremation?

All the body burns when cremated, leaving only bone fragments behind.

If there is an artificial joint, it will not burn or melt. Titanium makes up the hip and knee replacements. Stainless steel makes the screws.

The crematory operator removes and places the metals in a recycle bin.

20. Is there DNA in cremated ashes?

There is essentially no DNA in cremated remains. 

It is the bones and teeth that can hold some viable DNA for analysis. The crematory operator will process the bone and tooth fragments into a fine powder after completing the cremation. This makes it extremely difficult (though not impossible) to extract any viable DNA from the ashes. So, cremation destroys nearly all traces of DNA.

21. Do human ashes smell?

There is no detectable odor from cremated remains.

The remains may absorb odors from the way they are stored or the ambient surroundings, but there is no smell inherent to ashes.

22. Do bodies scream during cremation?

No, bodies do not scream when cremated. This is yet another urban myth about cremation.

It is possible for the body to create slight popping or cracking sounds brought on by the intensity of the heat, but it’s nothing distinguishable from the general sounds of the coffin being consumed by the flames.

23. Are there other things mixed in with the ashes?

The cremation process completely incinerates the body and clothing. The only thing left would be artificial joints or surgical screws. The crematory operator removes all of the metals before he will process the cremains. 

There should be nothing else included in the cremated remains. 

24. Can you view the body before cremation?

Yes, you can view the body beforehand. You can spend a few minutes with the body on the day of the cremation, or even have an entire memorial ceremony at the time of cremation. You can view the body even if it hasn’t been embalmed.

25. Can you watch a cremation?

Yes, you may partially witness cremation. You may watch the body be placed into the retort AKA cremation chamber, though you won’t be able to stay for the whole process as it takes a few hours to complete.

Many mortuaries now have a designated witness area. This is a room with a window looking into the crematory for this purpose. Sometimes, it’s even possible for the next-of-kin or other family member to proverbially “push the button” to start the process.

Learn more: Can You Witness the Cremation — And Should You?

26. Which is better, cremation or burial?

Cremation is cost-effective and saves on ground space. It also allows you to keep your loved one with you. Cremation is an irreversible process, so take the time to truly consider what your loved one would have wanted, what you think is best to honor their memory, and make the right choice once you’ve been well informed of your options.

These are difficult end-of-life decisions: cremation, or burial? Please honor your loved one’s wishes if they left instructions on how they wished to be laid to rest.

Read more: Burial or Cremation: Which is right for you?

27. Who gets the ashes after cremation?

Legally, the next-of-kin (commonly a spouse or parent) is the one who signs the cremation authorization and subsequently receives the remains.

Sometimes there is more than one next-of-kin, such as in the case of several adult children needing to sign for a parent. In this instance, legally every individual must sign the cremation authorization before the process can take place.

Upon completion of cremation, one individual may receive the ashes, or the funeral director may place the ashes into separate urns for each next-of-kin. But again, that is up to the family.

28. Who puts the ashes into the urn after cremation?

The crematory operators or funeral director will place the cremated remains into the urn.

If you don’t have the permanent urn yet, they will place the remains in a plastic bag inside of a plastic temporary urn or basic container. You can take the ashes home and transfer the remains yourself once you have the permanent, more personal urn, or bring it back in to the funeral home for them to do it for you.

29. Can you bring in your own urn?

Yes, you can bring in your own urn. The funeral home will have you sign a waiver to protect them from any damage done to the urn.

To find the perfect cremation urn for your loved one, you can start by looking at these best-selling urns from Urns Northwest.

30. Is cremation acceptable for all religions?

No. While many world religions have evolving views cremation, there remain a handful that still either strictly prohibit the practice, or strongly advise against it. These include Islam, Eastern Orthodox Christianity, and The Church of Latter-day Saints.

Related: What Does the Bible Say About Cremation?

31. Does cremation cause pollution?

Unfortunately, yes. Cremation does, in fact, create a relatively large amount of air pollution. Enough that environmentalists have been trying to come up with alternatives and solutions.

The cremation process requires large amounts of fuel, which then results in millions of tons of carbon dioxide emissions each year.

32. What is aqua cremation?

Aqua cremation is a type of cremation that uses heat, water, and an alkaline solution to create an environment that essentially mimics and speeds up how the body would decompose in the earth. Once the process is finished, only the bones remain, which can then be turned to ash by pulverization.

33. What do we do with the ashes after cremation?

That’s entirely up to you and your family. Many people choose to bury the urn of their choosing or place it in a columbarium, some scatter the ashes in a meaningful location, and now there are even options for turning the ashes into diamonds or other precious jewelry.

However you decide to honor your loved one and their ashes, be sure to take your time in making the decision. If you are looking for even more creative ideas, consider looking through these.

Related: Weird Things to Do with Ashes

34. Can you cremate a body yourself?

In the United States (and many other countries), no. In fact, it is considered a felony in all 50 US states to improperly dispose of human remains in manners such as “DIY” cremations.

Only licensed operators can carry out cremations in an approved facility that is capable of the task. It also requires special training and licensing. Getting the license in most states requires training from the CANA or NFDA.

35. Can you place possessions in the coffin before cremation?

Yes and no. Small items, memorabilia, letters, or possessions of the deceased can be placed in the coffin or container prior to cremation. But large items, rubber, glass, pottery, or large metal items are not permissible.

It’s best to check with the funeral director or crematorium operator concerning what is allowed and what is not.

36. Does the funeral home or crematorium take photos?

Typically, no, the crematorium or funeral home won’t take pictures prior to cremation. This is an issue of privacy, and funeral homes respect each family’s wishes.

Some families hire a photographer for the funeral. In that case, you can give the photographer permission to take pictures of the open casket, the funeral service, the reception, and more.

Photos can be a lovely way to commemorate the event, capture a rare family gathering, and honor your loved one’s memory.

Read Next: 8 Things to Know About Cremation Urns

Everything You Need to Know about Cremation

30 thoughts on “How Does Cremation Work? +35 Weird Questions About Cremation”

  1. My parents are in a double niche. Would it be possible to put another urn( their son ) in the same niche

  2. Hi Lori,

    Absolutely! It’s certainly possible to put an additional urn in a niche; the main thing is to contact the funeral home or cemetery and find out whether there is space in the niche and also whether they will permit it. There may be an additional charge, or an opening fee, depending on their policies. Best to contact them directly and find out.

  3. I seem unable to find out specifically what is done to a body prior to a private viewing before cremation. For example, is anything done to keep the mouth closed? Eyes totally closed? I am currently doing preplanning and considering a private viewing, but I don’t want that to cause such cosmetic work to be done and if it is required then probably would not have a private viewing. It seems these questions as to the technical aspects are not answered, probably because it might be considered to “gory” for most to understand properly.

  4. Hi William,

    I think that would be a great question to ask the funeral home what their standard practice is. I’m sure they will accommodate any reasonable request.

  5. I’ve heard that thin bodies smell like fireworks during cremation, and large bodies smell like bacon. Is this true?

  6. Hey Kevin,

    Karen (the author of this post and a funeral director) said she hadn’t noticed those particular smells, but that there is a general odor of cooking meat. Which makes sense, because that is what is happening during the cremation process. I’ve seen that comment you mentioned on other blog posts, ostensibly from a mortician (anonymous, of course). It may or may not be true, and there is a bit of subjectivity to smells so… perhaps. The bacon part makes sense (bacon is mostly fat), and the fireworks smell might too depending on the machinery used.

  7. I have a two-part question. My parents have a special urn (still empty) that won’t be big enough to contain all the ashes of both of them, but I would like to keep them together, when the time comes. Is it acceptable to blend two people, and is it a common practice to contain only part of the cremains, perhaps spreading the rest?

  8. Hi Jamison,

    Yes, absolutely. It is acceptable and it is a common practice to divide and/or mix the remains. It’s called commingling when you combine the remains of two people. Read more about dividing the remains here; families will divide the remains so that each family member can have a small keepsake urn or jewelry piece, or the family may scatter some and keep the rest, and so on. I hope this helps!

  9. I don’t want a showing so thinking of being cremated. I have a cemetery plot next to my mom and dad. Can my ashes be buried in the cemetery? If so, what’s standard procedure, be buried in an urn or other container and will the normal criteria for a burial have to be done since there won’t be a coffin?
    If I were to donate my body ( I have a genetic disease that’s fairy rare) could my body or ashes still be buried in my plot after science is done with it?
    One more question. If I donate my organs can I still be cremated and who pays for that?

  10. Hi Pam,

    Yes, your cremated remains can be buried in a cemetery. Talk to the cemetery management about how to arrange it. The typical burial procedure is an urn that is placed inside a protective vault. Read more about that here.

    And yes, if you donate your body to science then, when the research is complete, your family will get your cremated remains back and then you could be buried in the cemetery plot. If you are an organ donor, you can still be cremated afterwards; you (or your family) would still pay for the cremation.

  11. I had my husband cremated and put in an urn purchased from the funeral home. When I pass, I want both our ashes to be scattered together. Is the urn from the funeral home permanently sealed or will it be able to be opened and ashes scattered with mine?

  12. Hi Judy,

    Great question! It depends, but if you got a “companion urn” and the funeral home knew that you intended your remains to go in the urn as well, then it’s highly unlikely that they sealed it. Most companion urns are designed to be able to be re-opened. Also, with most urns the remains are already in a plastic bag which is placed inside the urn, so there is no need for a sealant as the plastic bag keeps the remains secure.

    I hope this helps, and for more information see this article.

  13. Yup, you’d be surprised at the number of people that regret irreversible processes. It might seem silly to say it out loud, but some people really do need to hear it.

  14. Hi Nancy,

    Typically any medical devices or prosthetics will be removed prior to cremation. Acrylic melts at 320 degrees and the cremation machine is much hotter than that, so no, a prosthetic eye will not withstand cremation.

  15. I believe so. As much as possible before cremation all surgical implants are removed. Then anything that still remains is sorted out afterwards. You’ll have to speak with your local crematorium about it to verify.

  16. Hello. My mother who just passed was on the fence about burying or cremation what we came to decide however may not be possible. We are wondering if there was a way to bury the body and cremate the organs or have them turned into a fertilizer for tree. She had a green thumb And we want to always have a piece of her with us however the burial zone would take place in her home town very far from where we reside. I have heard of people planting trees over biodegradable caskets but we won’t be able to plant a tree where they are burning her because its a military cemetery.

  17. Hi Alexandria,

    No, a crematorium cannot cremate part of a body, only the entire body or remains. See here for related information.

  18. Hey Charles, great question! Most morticians do not remove gold crowns or fillings. The cost of removal does not justify the value of the small amount of gold, so most crowns are buried or cremated along with the decedent.

  19. I have had my husband cremated 10 months ago and he is put in a cremation grave, I haven’t had a headstone put on yet but I have been to see a psychic and my husband came through and he said he didn’t want to be put in a grave he wants me to put him in our gdn because he loves my gdn and is with me when I’m gardening. Can I have my husbands ashes back.

  20. Hi Carolyn,

    You’d have to contact the cemetery to see what they would charge to dig up the remains. Depending on their policies, they may or may not be willing to do so.

  21. I have an automatic implant cardio defibrillator/and pacemaker run by a small lithium battery….will the battery be removed since lithium has been proven to produce a very high temperature.

  22. Hi Harrison,

    Yes, implants with batteries such as a pacemaker will be removed prior to cremation.

  23. In Jan. 2021 our Mother passed. She had chosen cremation and I am glad she expressed her wishes to more than me,(as I am the youngest of 7kids all adults) so she had her way. The most difficult part was getting one of my brothers signature on the papers as he lives in CA and we are in NC. Thank goodness for the internet and computers! He was able to electronically send his signature to the funeral home. People are so spread out these days it is something that more people need to be aware of. You do not have to wait for a loved one to fly or drive back to sign in person thus saving time and money.
    Also she wanted her ashes interred into her husband’s grave. Luckily I knew this and planned how to do it since his grave was over 50 years old and in a private church cemetery. We simply took her urn, a shovel, and dug a hole to fit with enough coverage to protect and make it safe. Most places will not allow this so we got lucky there. I still wanted to pour her ashes into the hole so she could “trickle down through the earth to join him fully” but got out voted. No worry as he is not MY Dad only theirs and I prefer her separate from him. Not sure why I feel that way, just do. Lol saved us a lot of money to have the grave opened and then closed by professionals like if it had been a big corp owned cemetery. People need to know their options. All of them.
    Thank you for your article as it was very informative and well written.

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