Modern Living

"Hot water bottles are now available with a high design factor." – Couch Magazine

"Saves heating costs and helps with back pain just as well as an ibuprofen." – Emotion Magazine

"Once you've tried it, you'll never want to miss the Foundly Hot-Water Bottle again" – Freundin Magazine

✓ Wearable in multiple ways: from the belly to the neck and hips

The innovative half-moon opening and adjustable strap let you wear it comfortably around your neck, shoulders, lower back, or waist. Its soft-touch surface and massage ribs provide targeted relief, making it perfect for easing muscle tension and menstrual cramps.

✓ Highest safety standards

Our Hot-Water Bottle is developed according to international safety standards, including the British Safety Standard (BS 1970:2012), ensuring durability, leak protection, and heat resistance. The high-quality material undergoes rigorous testing for elasticity, pressure resistance, and aging to prevent cracks or deformation. A secure closure system and an extra-large funnel make filling safer and easier, minimizing the risk of spills. Certified, Foundly prioritizes both comfort and safety—so you can enjoy warmth with peace of mind.

✓ Lightweight & Practical

Thoughtfully designed to be lightweight and Weighing just 200g when empty, the Urban Cross Bottle (UCB) is designed for effortless wear and daily comfort. With a capacity of 800ml, it is recommended to be filled to a maximum of two-thirds to ensure safe handling and prevent burns.

Compared to traditional hot water bottles, the UCB is lighter, slimmer, and ergonomically designed, making it more wearable and practical. While standard bottles typically hold 1–2 liters and are bulkier (approx. 320mm x 200mm), the UCB’s sleek dimensions (L: 380mm, W: 105mm, Thickness: 1.7mm) allow for targeted warmth without excess weight.

Made from 100% certified natural rubber, it not only prioritizes comfort but also sustainability. Whether at home or on the go, the UCB offers a modern take on warmth—wearable, lightweight, and thoughtfully designed.

✓ Natural warmth

Made from 100% natural rubber, the Urban Cross Bottle harnesses the timeless power of water to provide comforting warmth—free from electricity, cables, or batteries. Unlike electric heating pads, it does not emit electromagnetic radiation (EMF), making it a radiation-free alternative for natural heat therapy.

By using water as a natural heat source, the UCB offers a gentle, even warmth that lasts for hours, without the risks of overheating or electrical malfunctions. A sustainable choice that saves energy while providing soothing comfort—anytime, anywhere.

✓ Free of toxins

Certified as a natural product, the Urban Cross Bottleis made from 100% certified natural rubber, ensuring it is free from harmful chemicals and synthetic additives. Unlike many conventional hot water bottles, it contains no PVC, BPA, or phthalates, making it as afe and eco-friendly choice for comfy warmth and well-being.

✓ Comfy & Ergonomic

Ergonomically shaped for ultimate comfort, the Urban Cross Bottle adapts naturally to the body. Designed with tactile massage ridges, it provides a soothing sensory experience while delivering targeted warmth. The soft-touch surfaceenhances relaxation, making every use a moment of comfort and well-being.

✓ Natural Rubber

Natural rubber is derived from the rubber tree (Hevea brasiliensis) and is biodegradable, making it a more sustainable choice compared to synthetic alternatives. With alower environmental impact, it supports eco-friendly production and long-term durability. Foundly uses certified natural rubber to meet the highest quality and sustainability standards, ensuring both comfort and responsibility in every product.

✓ Fair Rubber Certified

With every Urban Cross Bottle sold, a fair trade premium directly supports rubber tappers and plantation farmers, ensuring fair wages, better working conditions, and sustainable farming practices.

As a proud partner of Fair Rubber e.V. (fairrubber.org), Foundly is committed to ethical sourcing. The Fair Rubber certification guarantees that the natural rubber used in our products is harvested under socially and environmentally responsible conditions. This initiative helps fund healthcare, education, and community development projects for rubber-producing communities.

By choosing Foundly, you're not just investing in high-quality, sustainable warmth—you're actively supporting fair trade and a better future for rubber farmers worldwide.

4.9/5 See What Our Customers Are Saying

Feedback Love

Lisa

„Minimalistisch und cozy AF!“

Paula

„Jetzt, wo ich endlich auch meine Foundly Wärmflasche habe, verstehe ich, warum sie ständig ausverkauft sind. Tolles Design und funktional. Absolute Empfehlung, wenn ihr eine ergattern könnt :P!“

Clara

“A lifesaver for my endometriosis and a beautiful addition to my home. For me, it’s the perfect blend of design and function.”

Sabrina

„Ich bin so froh, dass ich diese Wärmflasche entdeckt habe. Die Größe ist perfekt und das Material fühlt sich angenehm an. Eine absolute Kaufempfehlung für alle, die nach einer schönen und funktionalen Lösung suchen!“

Isabel

„Ein Must-Have für alle Wärmflaschen-Ultras!“

Jun

"I have a whole collection of hot-water bottles and matching scarfs to treat my endometriosis. However, I have been looking for ethical and social responsible alternatives. Therefore, the offer to test the product came just at the right time..and UCB exceeds my expectations: Ethical, a contemporary design and it definitely fits my wardrobe!“

Pamela

“My ultimate cozy accessory! Whether I’m lounging or working, I can’t imagine spending a winter day without it.”

Dr. Martin Morgenstern, Evolutionary Psychologist

"A great principle and easy to use. Especially well suited for anyone who regularly suffers from (stress-)related tension. I can "warmly" recommend the product."

Monika

“Great companion for all the menstruating people out there! I am a hot water bottle girl, not only during the winter days but also throughout my period. I struggled to secure the water bottle in the right spot for years. I’ve been patiently waiting for the next drop of Bottle + Velcro belt, and since I got hands on mine, I’ve barely take it off. ”

Tanya

“This is the most stylish and well thought-out hot-water bottle solution ever. Absolutely worth the money. People keep on asking me where they can buy it :)) Thank you all! ”

Ulrike

„Ich hatte mir zu Weihnachten direkt zwei geschenkt 😊 Das Design ist superschön und sie fühlen sich viel weicher an als andere Wärmflaschen. Die Kombination mit dem Gurt ist einfach genial: Man kann sich drehen und wenden, die Flasche bleibt, wo sie sein soll, ob auf dem Sofa oder beim Spazierengehen. Ich geniesse sie auch, wenn ich länger am Schreibtisch sitze, Rückenverspannungen ade ;-) Für mich jetzt schon ein Alltagsliebling und auf der Geschenkideen-Liste ganz oben...."

Vivien

„Ich bin so dankbar, dass es endlich eine Wärmflasche gibt, die hochwertig, schön und fashionable ist! Ich trage sie grad im Winter wirklich jeden Tag, zuhause und auch unterwegs! Vor allem bei Menstruationsschmerzen oder Muskelkater ist es super sie einfach tagsüber umzuschnallen. Ein echter Gamechanger! Der Gurt ist gut verarbeitet und super soft und hat sogar eine kleine Tasche :) Nie wieder ohne <3"

Lilli

"Too beautiful to hide. Finally, a hot-water bottle that suits my taste in interior design and fashion."

Eva

„Direkt nachbestellt!
Ich habe bereits eines der ersten Sets ergattert und bin total begeistert. Daher habe ich direkt für Weihnachten nachbestellt und freue mich aufs Verschenken. Die Wärmflasche nutze ich übrigens auch gerne alleine, wirklich ohne Sleeve. War da zuerst etwas skeptisch, aber die Foundly Wärmflasche ist wirklich angenehm. Wünsche Euch viel Erfolg weiter.."

Annika

„Ich bin absolut begeistert von der Foundly Wärmflasche! Sie sieht nicht nur wunderschön aus, sondern erfüllt auch ihren Zweck zur Schmerzlinderung hervorragend. Oft finde ich es schwierig, Produkte zu finden, die sowohl funktional als auch ästhetisch ansprechend sind. Bei dieser Wärmflasche habe ich das Gefühl, ein echtes Designerstück in meinem Zuhause zu haben, das gleichzeitig eine großartige Lösung für meine Schmerzen bietet.“

Linda

„Mein neues Lieblingsaccessoire für kalte Tage.“

Anna

„Wurde mir von einer Freundin geschenkt und ich liebe diese Wärmflasche! Design, Haptik und Konzept sind wirklich toll – und das ganze Teil ist auch fair produziert. Ich werde sie auf jede Fall auch zu Weihnachten verschenken“

Ivana

Ich finde das Produkt super und werde es in Zukunft gerne weiter verschenken 😊

Your Questions, Answered

Can a Hot-Water Bottle ease pain?

Studies have proven that heat in general has a similar effect to a painkiller, effectively “deactivating” pain at a molecular level. In this way, completely naturally and without any chemicals, heat shuts down the regular pain response and helps with issues such as menstrual pain, neck tension, and abdominal cramps, and even diseases such as endometriosis or Crohn’s disease. However, hot-water bottles by themselves do not ease pain. UCB does not claim the capability of a medical device. In case of doubt, consult your doctor or pharmacist.

Are there any scientifically proven results about the benefits of heat?

Yes. The fact that heat relieves abdominal pain, such as colic or menstrual pain, has been scientifically proven by a UCL (University College London) scientist. Dr. Brian King, of the UCL Department of Physiology, led the research that found the molecular basis for the long-standing theory that heat provides relief from internal pains. For more information visit: Uniersity College London

How do you ensure the safety and durability of your hot water bottles?

Which belt size is right for me?

Currently, we have 2 belt sizes available in our shop. Size 1 has a length of 110cm and is designed for clothing sizes S/M. Size 2 has a length of 125cm and is designed for clothing sizes M/L.

How does Foundly support fair trade and sustainable rubber farming?

By choosing Foundly, you're not just investing in high-quality, sustainable warmth—you're actively supporting fair trade and a better future for rubber farmers worldwide.

What makes the Foundly Hot-Water Bottle unique?

The Foundly Hot-Water Bottle is the upgraded version of the conventional Hot-water bottle. Ergonomically shaped (including massage riffles) and designed to keep you warm and cosy during your daily routines – whether it’s at the office, during outdoor activities or while having a relaxing rest at home. In combination with our comfy, removable belt, our hot-water bottle can be worn in multiple ways: around your neck and shoulders, around your upper or lower back or around your belly