The Science

Therapeutic heat has long been practiced in all parts of the world. The effectiveness of the healing qualities existed long before the mechanics of heat therapy were understood. The American Indians so revered hot springs that the land near the spring was considered a neutral zone. Even warring tribes respected this strong medicine and laid down their arms when they were near the medicinal springs.

Hippocrates, the father of modern medicine, used hydrotherapy as a primary healing agent. His patients were positioned so that clay dams could be built around the injured or painful part of the body and hot water was poured into the dammed-in area.

The use of heat as a therapeutic medium continues today throughout the world. While the physiological effects of heat are now understood on a more scientific level, heat therapy has lost none of its effectiveness.

Hot water bottles work very well and are still used regularly all over the world, and are particularly popular in Great Britain. Due to the size and volume limitations of conventional hot water bottles, it is easy to see how the Fomentek bags with the improved technology, materials, size, and capacity, offer a tremendous improvement over the old standard.

Moist heat is about conductivity.

We often hear that “moist heat” is better than “dry heat” to relieve pain. Let’s dispel any notions that the moisture content of a fomentation device determines its therapeutic quality. It is important to understand that inside the body everything is moist. The term “moist heat” actually has more to do with how well the heating medium transfers heat into the body through conduction rather than whether the medium is actually wet.

If a person opens a pre-heated 350°F oven and sticks their hand in for 3 seconds then pulls it out, heat will be felt, but there is no likelihood that 3 seconds in this environment would cause injury. Now let’s take the same oven and the same hand, but instead of just sticking the hand into the oven, imagine grabbing a hot oven rack for 3 seconds. Third-degree burns would occur. The 350ºF temperature is shared by both the air inside the oven and the steel rack. The steel burned the hand because it is a solid whereas the air is a gas. Stationary hot air does not conduct heat as well as hot steel.

When a person lies on a dry flannel-covered heating pad, the body is in contact with dry cotton fibers. The skin is bridged over dry stationary air space and supported by a small percentage of the total area. Now imagine that the flannel heating pad cover is moist. Hot wet flannel has many times the contact area and thus more conductive because water conducts heat far more efficiently than dry cotton. Let’s take our scenario a little further by imagining that we remove the flannel outer covering (pillowcase) from the heating pad exposing the hot plastic pad cover. The plastic surface of the electric heating pad is about 140°F. OUCH!

These examples help us to understand that it is not the moisture itself that assists therapeutic heat transfer, but how well the substance in contact with the body conducts heat.

The Fomentek bag, filled with warm water, has the conductive properties of a solid with the heat-retaining qualities of water.

Heating the muscles has the effect of increasing blood flow by increasing the metabolic rate and thus the demand for new blood. The application of heat also causes the vascular tissue (veins, arteries, and lymph vessels) to dilate. The influx of more blood and the elimination of cellular waste products from the interstitial fluid into the lymphatic system and ultimately into the veins cause relaxation of the muscles on a deep level.

Heat therapy also relieves pain by tapping into the body’s parasympathetic nervous system causing the release of endorphins, the body’s own “feel good” pain relief hormones.

Heat therapy interferes with the body’s pain transfer mechanisms. Sensory pathways for pain and temperature are shared and when the heat message occupies these pathways, the pain message becomes distorted and the pain diminished.

The Fomentek bag user must understand the differences between this product and the traditional (old-time) red rubber hot water bottle.

The red rubber hot water bottle is typically filled with very hot water, often from a boiling kettle, and then capped and wrapped in a dry towel before being placed against the body.

The Fomentek bag, however, comes into direct contact with the skin and that means that the temperature of the filled Fomentek bag is the same temperature the body will experience.

The Fomentek bag is used directly against the skin at much lower temperatures.

Fomentek bags should never be used with scalding water, only comfortably warm water no hotter than 113.7ºF (45.4ºC.)


Sickle Cell Anemia is a complex disease characterized by regional pain due to the lack of blood flow (ischemia.) Sickle Cell Pain Crisis is a Vaso-Occlusive Crisis. Pain crisis protocol often involves the use of heat. Using a warm Fomentek bag to deliver heat to the occluded area is a superior method of treatment because the treatment area is well defined and the heat delivery is immediate. There is no chance of being burned by heat buildup as can occur with a heating pad because the Fomentek bag gradually cools down over time.

The red blood cells of a Sickle Cell patient are actually shaped like bananas instead of being shaped like a football. Healthy football-shaped blood cells flow well and easily slide past each other.

A Sickle Cell Pain Crisis occurs when the blood flow within a localized area is restricted. This compromised blood flow is due to the banana-shaped blood cells hanging onto each other. The deep pain of Sickle Cell Anemia is similar to the pain felt when a person sits on their leg for a long time and feels “pins and needles” followed by short-term deep pain. A person without Sickle Cell can simply move around, getting the blood flowing again and the pain stops. A Sickle Cell patient with the characteristic chronic episodes of pain due to compromised blood flow cannot simply move around to gain relief because the red blood cells continue to hang onto each other, keeping the blood from flowing well.

We are often asked, “What is Sickle Cell Anemia?” or, “What is Sickle Cell?” To illustrate what is happening during a Sickle Cell Pain Crisis episode, imagine that a slow-moving river has thousands of crooked logs that are headed downstream. The crooked logs get hung up on each other, drag against the river banks, and quit moving. If the amount of water in the river increases, the river becomes wider and the crooked logs have extra room to flow. As the logs move down the wider river, they begin to untangle and again move down the river.

Let’s compare the river to blood vessels within the body. Ingesting water and heating the painful area with a Fomentek bag causes the blood vessels to dilate or enlarge and the crooked red blood cells have extra room to flow. Staying hydrated is very important for the management of Sickle Cell Anemia.

Sickle Cell Disease has the same general causative factors but is not the same for every patient. The disease presents differently and the treatments vary for different severities and ages. It is imperative that those suffering from this disease be under the care of a physician. Some protocols for treatment call for alternating heat and cold. Talk to your treating physician about using a Fomentek bag if hot or cold treatments are recommended.



During childbirth, a Fomentek bag can be used as a hot compress for the perineum to stretch the tissue and prevent vaginal tearing and prevent perineal lacerations. The Fomentek bag can be used in conjunction with oils and perineal massage to help decrease the chances of vaginal tearing. Heat can be consistently relied upon to facilitate the stretching of the perineum. The goal is to reduce vaginal and perineal tearing and prevent the need for an episiotomy.

What is an Episiotomy?

An episiotomy is a surgical incision of the perineum made to avoid tearing during childbirth. The episiotomy became ingrained in American hospital obstetric practice beginning in the 1920s. By the 1940s and 1950s, routine episiotomy was little debated and increasingly used. By the 1980s, episiotomy accompanied 64 percent of vaginal births in the US.

The popularity of episiotomy was heavily driven by local professional norms, experiences in training, and individual provider preference. The belief that a smooth incision would be less injurious to the mother was prevalent. During the latter half of the 20th century, the avoidance of tearing during childbirth became a major consideration in the minds of both mothers-to-be and caregivers alike.

As it turns out, in most cases, small perineal tears heal more quickly and completely than either midline or mediolateral incisions. Also, the evidence has shown that the inherent weaknesses in the scar tissue of healed episiotomies fail during subsequent births.

How can tearing of the perineum be averted or minimized by a Fomentek bag?

How many times have you observed the movie scene where a woman goes into labor and the person in charge yells out, “Go boil some water!” Then yells, “And bring me some clean towels.” Traditionally, the midwife applied hot compresses to the perennial area to aid in stretching, thus minimizing tearing before the baby comes.

A hot wet towel generates a cloud of steam. The rising steam shows evidence of evaporative cooling. Using a hot towel to soften the perineum requires constant reheating. However, the Fomentek bag, with its pliable exterior, larger volume, and having no heat lost through evaporative cooling, serves to heat the perineum with improved efficiency. The Fomentek bag is simply filled with warm tap water and it is ready for extended use. The soft Fomentek bag provides consistent heat transfer and conforms to the treatment area.


A warm comfortable Fomentek bag is ideal for treating the intense lower back pain women can experience during labor, often referred to as “back labor.” Use continuously by using two Fomentek bags in rotation.

What is Back Labor and What causes Back Labor?

The following definition of Back Labor is from the American Pregnancy Association ( :

“Back Labor” refers to the pain and discomfort that laboring women experience in their lower back. Although most women will feel a degree of soreness or slight cramping in the back at some point during labor, about a quarter of women report experiencing severe discomfort in the lower back that is most intense during contractions and often painful between contractions. Back labor can often be accompanied by an irregular contraction pattern, a labor that is slow to progress, and a prolonged pushing stage.

A frequent cause of back labor is the position of the baby. Positions such as occiput posterior (when the baby is facing the mother’s abdomen) can cause pressure from the baby’s head to be applied to the mother’s sacrum (the tailbone).

The result can be intense discomfort during labor. However, a baby in an odd position does not always result in back labor. Similarly, back labor is not always the result of a baby’s positioning. Some research has shown that a woman who experiences back pain during her menstrual cycle may be more likely to experience back labor regardless of the baby’s position.

After the hard work of labor comes a long list of possible discomforts during the postpartum period, a time during which women need to focus on their recovery and healing. Even muscles in the back, neck, jaw, arms, and legs can be sore for days.

Many nursing mothers prefer a drug-free approach to their pain management and are overjoyed when learning of the many ways Fomentek bags can help recovery and keep their intake of pain medication to a minimum.


Please follow the advice of your physician. Through the use of heat and cold, perineal lacerations (tears) can be reduced and postpartum swelling addressed. Your OB may prescribe heat or cold for the following post postpartum conditions:

– Reduce vaginal soreness with a COLD Fomentek bag.
– Reduce vaginal swelling with a COLD Fomentek bag.
– Ease soreness of the perineum (the area between the vagina and rectum) with a COLD Fomentek bag.
– Ease soreness of hemorrhoids with a COLD Fomentek bag.
– Ease pain of breast engorgement with a COLD or WARM Fomentek bag.
– Ease sore muscles in the arms, neck, or jaw with a COLD or WARM Fomentek bag.
– Ease afterpains with a COLD Fomentek bag.

To ease the pain of hemorrhoids physicians often recommend that an ice compress or cold pack be used in conjunction with witch hazel pads.


For several days after childbirth (vaginal delivery or cesarean) women may experience contractions referred to as afterpains. These contractions help the uterus shrink to its pre-pregnancy size. Pain levels of afterbirth cramping vary. Applying a warm Fomentek bag to the abdomen can provide immediate drug-free comfort and pain relief.

Warm Use: Fill the Fomentek bag 1/3 full with warm tap water
Cold Use: Fill the Fomentek bag 1/3 full with cold tap water and store it in the refrigerator

The cold Fomentek bag can be applied directly against the skin and easily cleaned with any cleanser or sanitizer of your choice and rinsed thoroughly before the next use. Using a cold Fomentek bag will not cause frostbite. Safely fall asleep on a warm or cold Fomentek bag as it slowly returns to room temperature.

Doctors often suggest that patients make a homemade ice pack or cold compress using a one-gallon resealable storage bag with either water or a water and alcohol mixture. A quick internet search reveals dozens of recipes to make a homemade ice pack or homemade gel pack using a freezer bag such as a Ziploc bag with mixtures including water, alcohol, and/or dish detergent. Homemade ice packs and gel packs are soft and pliable to conform to the skin BUT CANNOT WITHSTAND PRESSURE. Fomentek bags are far superior to homemade ice packs for their durability alone. The price of Fomentek bags makes them a great alternative to a homemade ice pack. Make for immediate use or store for future use. The Fomentek bag comes in three sizes, the largest providing an area of 1.5 ft x 2 ft of durable therapy.

Fold over the large Fomentek bag to chill a knee or ankle sprain. After knee replacement surgery some patients use a Fomentek bag instead of renting an expensive ice machine or cold therapy machine for their knee.

Our smallest size, (11″x15″) fits in a one-gallon container. Our Small 2-Pack contains two small bags so they can be rotated from the refrigerator and never leave you without a nice chilled bag.

Warm Use: fill the fomentek bag 1/3 full with warm tap water
Cold Use: fill the fomentek bag 1/3 full with cold tap water and store it in the refrigerator

The cold Fomentek bag can be applied directly against the skin and easily cleaned with any cleanser or sanitizer of your choice and rinsed thoroughly before the next use. Using a cold Fomentek bag will not cause frostbite. Safely fall asleep on a warm or cold Fomentek bag as it slowly returns to room temperature.

Our Fomentek® Water Bag users often come up with a multitude of creative ways to use the bags. One popular usage is to fill it up with air (blow it like a balloon) and use it as Lumbar support while driving or flying long distances. Truckers and road trippers often use this trick to make their driving more comfortable.

Another popular usage is travel air pillows. Campers and hikers love the lightweight convenience of using the bags as air pillows for outdoor excursions. The bag is compact so it doesn’t take much space in your backpack. When you’re ready to use it, simply fill it up with air (blow it like a balloon). The bag is very durable and can withstand up to 600 lbs of pressure, yet is still soft and pliable so you can get a comfortable night’s sleep wherever you lay your head. Cover with a pillowcase and you’re ready to sleep under the stars.

Our bag is made with FDA-approved, BPA-Free, food-grade plastic, Latex-Free, Phthalate-Free, Odor-Free, Non-Allergenic, and Non-Toxic. These qualities make the Fomentek bags perfect for portable emergency clean water storage.

Thin, Soft, and Strong

Two durable, ultra-thin polymer layers provide strength while remaining pliable and soft to the touch.
Every Fomentek bag has a 90-day manufacturer and 30-day satisfaction guarantee!

Fomentek bags are my #1 for menstrual cramp pain relief. I’ve given one to every woman in my life who has bad period cramps. Relief is instant…just nothing like it.
Vicki C.
I was in so much pain after my episiotomy. My doula gave me a Fomentek bag as a cold compress for my perineum. My OB recommended little perineal cold packs so I went ahead and got those too. The Fomentek bag was so much better than those perineal cold packs. I used the Fomentek cold and warm on my perineum for pain relief during those few weeks.
Rachel A.
Fomentek bags are the only warm compress for me. I’ve tried so many I was like a collector of heating pads and heat packs for decades. The heat of a Fomentek bag is just tap water but it is immediate and deep. I bring an empty large with me to my chiropractor, fill it there, and use it before an adjustment instead of the hydrocollator pads which take too long to penetrate and just can’t don’t give the coverage in all the nooks and crannies. I would tell people to try it and they will stop collecting! This is it.
Kirk M.
Having Fibromyalgia can take over your life. The day I found a Fomentek bag for my Fibromyalgia pain relief was a changing day in my life. The large is gigantic and envelops my neck down to almost my tail bone in a deep heat that is drug-free pain relief.
Keiren S.