by Mark Hancock, M.D.
As the thermometer flashes 103.1F on my eleven year old daughter’s forehead, I realize that I have developed a different attitude to fever than is common today. She lies comfortable, warm in her bed. I know that the fever is helping her heal- the thought of giving a fever reducer does not cross my mind. Winter invites us to go inward. Days shorten, temperatures fall. Nature contracts life inward. The leaves fall and many animals go underground. Seeds await the spring. But beneath the frozen ground there is inner activity. Human beings are also drawn inward. In the winter we are drawn to gather ourselves physically, emotionally and spiritually. We are at the edge of light and darkness, warmth and cold. We can find and restore balance from within.
Warmth as a Sign of Life
Temperature is considered a vital sign for an important reason. A living body is capable of maintaining its own temperature. It can actively generate heat and organize the heat through movement, metabolism and circulation. And we feel well when all parts of us are properly warmed through.
Coldness can be a sign of something else- difficulty inhabiting our body and making it truly our own. I am reminded of how truly well a patient can feel after being fully warmed by the ginger compress placed over the kidney adrenal organs.
Fever: Turning Inward to Heal
Fever is the pinnacle of warmth turned inward for healing. Biologically fever is an ancient wise response where the body creates the internal conditions supporting immune activity, healing, and transformation.
We rest and turn within and during this time the body works to break down what no longer serves it. It reorganizes what should stay. Many parents, myself included, have noted how their children emerge from febrile illnesses not only physically recovered, but often developmentally changed as if they have crossed an inner threshold.
Warmth and Growth: A Natural Balance
Nature has a law called the Temperature-Size rule that holds across multiple kingdoms of nature. An organism in a warm environment will typically reach a smaller maximum size than an organism in a colder environment. A cold water fish can continue to grow and grow. A warm blooded finch is highly developed but is relatively tiny. Warmth halts unrestrained growth.
If warmth restrains growth, and cancer is unrestrained growth, then fever deserves serious attention in oncology.
I recall the riveting story of a patient who I cared for. He had colon cancer with many lung metastases. A few months before he came to me he had gotten a virus that had been all the rage- and he got very sick. Two full weeks of high fever at home. Then into the hospital, fortunately just for supplemental oxygen but also with fevers there another two weeks. And then home where he had low grade fever for a couple more weeks. Then a rest period without any chemotherapy. When he came to me it had been months since any treatment and he was very worried about his next scan. But fever is a healer. His next scan showed a true miracle- the lung metastases were almost all gone.
The conventional practice of medicine has largely ignored fever as a potential treatment or treatment enhancer- but the signs are there. There are studies showing that those receiving immunotherapy for cancer do much better if they have an unsuppressed fever from their treatment. It has been observed over and over in different studies how those with a cancer diagnosis have very little history of having had fever, either the year before or in their childhoods. And the largest study on spontaneous remissions from cancer showed that 80% of these were preceded by a fever- often an infection.
Mistletoe Therapy
Mistletoe therapy follows the fundamental principle: using controlled warmth to oppose cancer.Used in Anthroposophic medicine since 1917, mistletoe is now widely used in Europe and becoming more known in the US. The semi-parasitic plant contains lectins and viscotoxins—compounds that stimulate immune responses and directly impair tumor cells. Some mistletoe preparations reliably induce fever. Others act more subtly. There are many studies pointing to quality-of-life improvements and survival benefits. From an Anthroposophic perspective, mistletoe uniquely mirrors cancer: it is a parasitic plant that grows independently of normal plant growth patterns. When prepared and administered correctly, it appears to call forth the organism’s capacity to re-establish order.
Light and Darkness
The transforming effect of fever goes deep. It also affects light and darkness of the soul. There is ongoing research on induced whole body hyperthermia as a treatment for resistant depression. A single session of hyperthermia was found to reduce depressive symptoms for 6 weeks. I have seen the inner transformations that fever can bring about while doing whole body hyperthermia treatments with patients. It is not an easy therapy- it is a labor process- one that often shifts an inner transformation in patients. It can open doorways to healing.
Winter as Healing Perspective
A lot can be learned from winter.
It teaches us that healing does not always come from doing more or pushing harder. Healing can come from slowing down, warming up, and allowing the body to work quietly from within.
As we move through this darker season, we can ask ourselves:
- Where do I need more warmth—physically, emotionally, or socially?
- Where can I allow myself to rest and turn inward?
- What is ready to be transformed inside of me?
This post was originally published in the Holiday 2025 Newsletter