A sudden chill and rising temperature during chemotherapy can be a time-sensitive situation in itself. Cytotoxic chemotherapy lowers not only cancer cells but also the white blood cells made in the bone marrow, especially the neutrophils that defend against bacteria. Fever that appears while the neutrophil count is at its lowest is called febrile neutropenia, and a person can look relatively well yet change considerably within hours. For this reason, many clinical guidelines recommend drawing blood, taking blood cultures, and starting antibiotics early, before the exact source of infection has been identified. Feeling "still manageable" is not, by itself, a guarantee of safety.
Thresholds differ slightly between hospitals, but a single reading above 38.3°C, or 38.0°C sustained for about an hour, is commonly given as the point to call. The urgency rises further when shaking chills, a clear drop in urine output, breathlessness, or confusion appear alongside the fever. The leaflet or patient booklet handed out at the start of treatment often states exactly which temperature and which phone number apply. Finding that number in advance and posting it somewhere visible spares a great deal of searching at three in the morning.
Hearing "there is nothing we can do even if you come" or "we have no beds" is not unusual. It does not mean the fever is unimportant. Emergency departments triage by severity, and a patient with weakened immunity needs a space separated from other patients, which is harder to free up. A phone call also cannot establish how ill someone actually is, so staff are rarely able to promise acceptance in advance. The answer usually describes the state of that department at that hour, not the seriousness of the fever.
When the treating hospital is two or three hours away, receiving initial care at a nearby emergency department is worth considering. Checking the blood count, drawing blood cultures, and giving a first dose of antibiotics can often be done outside a tertiary cancer centre. If transfer is then needed, that hospital can arrange it, which is generally easier than a family calling around themselves. In Korea, the 119 emergency medical dispatch centre provides advice and hospital guidance by phone, and the National Emergency Medical Center's E-Gen portal or app lists facilities currently able to see patients. If the person cannot stand or is becoming drowsy, calling 119 is safer than travelling by car or taxi.
Preparation makes such nights far less bewildering. Keep a single sheet — diagnosis and stage, the name of the current regimen and the date of the most recent dose, any oral chemotherapy being taken, other medicines and allergies, and the latest blood test results — and photograph it on a phone. Clinicians meeting the patient for the first time can save considerable time with that one page. Add a thermometer, hospital and identity cards, a mask, any medicines prescribed to keep at home, and a note of when the temperature was taken and what it read. Fever reducers can mask the picture and complicate assessment, so they are best used only in the way the treating physician has already specified. Waiting for morning with cool towels is not a substitute for being seen.
On a calm day, at the next outpatient visit, it is worth asking one question: "If a fever starts at night, where should we go, and what should we bring?" Some cancer centres provide an after-hours telephone line or can name a local hospital they work with. Having that answer in hand means the next feverish night does not begin with the question of where to go.
This article is general information and does not replace medical care for an individual patient. Causes of fever and appropriate responses vary from person to person, so please consult your own medical team and follow the instructions given by your treating hospital.