Kateřina studied industrial design, the kind that usually leads to cars, trams. But healthcare called to her differently. "I always had this mindset: Who am I designing for? And if we figure it out, let's make it into reality and help more people," she says. The designer as observer. The designer as someone who watches faces, mimics, what people reach for when they're in pain.

What she reached for was heat. What her grandmother told her. What generations of women knew instinctively: keep your body warm. But somewhere between ancestral wisdom and modern marketing, the pill became magic. The quick fix. The thing that makes you functional.

"The marketing of paracetamol is so strong," Kateřina says. "It's presented as magic, take this and magic will happen. But it's not magic. It's a short-term solution. In the long run, what is this doing to your body? Your fertility? Your digestion? What will I be dealing with at 30 because of what I did at 20?"

Heat, by contrast, works immediately. You feel it. Your nerves calm. Your muscles release. It's the same principle as a hot bath, a sauna, the warmth that makes your body exhale. Except you can't take a bath to a business meeting. You can't carry a sauna on the train.

So Kateřina designed something you could wear. Something discreet, wearable, real. Something that sits at the intersection of healthcare and self-care, a line she's walked carefully for years.

"I love that question, the healthcare versus self-care balance," Kateřina says when I bring it up. "Nobody asks about that."

It's the gap Body Moody lives in. Heat is clinical enough to be backed by studies showing heat therapy works as well as ibuprofen. Wearable enough to fit into everyday life. Doctors treating endometriosis wanting to promote wellness product to be able support woman along side of hormonal treatment. Fashionable enough that you don't feel like you're wearing a medical device, but reflecting lifestyle and demonstrating wellness device as Body Moody.

"Some women already knew heat helped them," she explains. "They were using hot water bottles at home, taking baths, doing exercise to warm their bodies. But the problem with pain is that your period always chooses the conference. The business meeting. The day you can't cancel."

The feedback loop is what keeps her going. Women writing that they were able to reduce their pill dosage. Women navigating a cycle without pharmaceuticals for the first time. Women with undiagnosed endometriosis finding some relief, even if not complete, and being pointed toward professional treatment (feedback from customers, not medical claims)..

"I'm trying to say to them: it's not about being the most extreme, 'I'll only use heat and nothing else' or 'I'll only use pills and suffer through it.' It's about finding a combination that works for you in the long term. That's the bigger win."

If you're waiting for the part where building a company gets easier, Kateřina has news: it doesn't.

"It's like being a woman," she says, laughing. "Your whole life, you're going through transitions. First you're figuring out your period, Why am I angry? Why am I tired? Why do I want to have sex? Then you're more mature in your cycle. Then maybe you want to get pregnant and your hormones change. Then you have a baby and you want to get back to your career but you're different. You have different priorities. Perimenopause. Menopause. It's constant transition."

She pauses.

"Business is the same thing."

For years, she bootstrapped. Worked for other companies while building Body Moody on the side. Learned by being a sponge in healthcare startups, big companies, anywhere she could absorb information. An investor once offered her funding early on, on the condition she go all-in immediately.

"I just felt pressure that this wasn't the right call. I needed to grow into that. I needed to want to say yes only to my business. And I'm exactly in that stage now."

Now she's fundraising. Meeting investors. Navigating valuations and big-picture thinking while still handling the ten daily roles of a founder. The mental load is real. The hard part isn't being busy, it's the constant recalibration. The loneliness of building something so personal that every customer's story of pain becomes yours to hold.

"I don't know a single woman, not one customer, who isn't dealing with some kind of transition," she says. "And when they share their stories with me, when they tell me about their pain, their bladder infections, their endometriosis... there's a responsibility in that."

But there's also joy. The message from a woman who went to a conference pain-free for the first time. The feedback that heat worked when nothing else did. The quiet knowledge that she's helping women reclaim something simple: the ability to move through the world with mental clarity and choose alternatives alongside medications (feedback from customers, not medical claims).

Building Body Moody hasn't been a straight line. Kateřina's mother sewed the first prototypes, her encouragement still echoing: "You've got this. You have this courage within you." Her spirit, Kateřina says, will always be with the company. There have been moments on the bottom. Moments of wondering if she's doing it wrong. Moments of pure chaos.

But here's what she's learned: chaos is the stage. Not a failure of planning or a sign you haven't figured it out. Just the nature of building something real.

"Heat is so simple that everyone can realise it works," she says. "The problem is we've been told something else is normal. That suffering through it is normal. That two pills a day is normal. And I'm just saying: what if we go back to something generations of women knew? What if we make it wearable, practical, real?"

What if we stop asking women to fit into systems that were never designed for their bodies in the first place?

That's the business Kateřina is building. Not one that fights pharma head-on, but one that offers an alternative. Not one that claims to be a magic solution, but one that says: Here's another tool. See if it works for you. Find your combination. Take your body back.

And if that's not rebellion, I don't know what is.