An incubator is a controlled environment designed to support something fragile during its earliest stages of development. The term applies across medicine, science, agriculture, and business, but the core idea is the same: maintain precise conditions (temperature, humidity, atmosphere) so that a vulnerable organism or venture can survive and grow. Here’s how incubators work in each of these contexts.
Medical Incubators for Newborns
The most familiar type of incubator is the enclosed, transparent unit used in hospital neonatal wards. It keeps premature or underweight babies warm, humid, and protected while their bodies finish developing outside the womb. Babies born before 28 weeks of gestation are especially vulnerable to dangerous drops in body temperature because they have a much larger surface area relative to their body mass, very little body fat, and immature internal temperature regulation. Infants weighing under 1,500 grams (about 3.3 pounds) at birth are the most common candidates for incubator care.
Inside the unit, air temperature is held between 28 and 34 °C (roughly 82 to 93 °F), adjusted to the individual baby’s needs. A skin sensor, typically placed on the abdomen, feeds temperature data back to the incubator’s control system, which automatically raises or lowers the heat to keep the baby’s body temperature stable. Modern units also monitor and record humidity, sound levels, and, through connected biosensors, vital signs like heart rate, oxygen saturation, blood pressure, and breathing patterns.
In the delivery room, staff use several warming strategies at once for very premature infants: polyethylene wraps to reduce heat loss through evaporation, heated humidified breathing gases, thermal mattresses, head covers, and radiant warmers. The incubator continues that protection once the baby reaches the NICU, creating a warm, humid microenvironment that mimics conditions closer to the womb.
A Surprising Origin Story
The neonatal incubator traces back to 1880, when French obstetrician Dr. Étienne Stéphane Tarnier observed warming chambers used for poultry chicks at the Paris Zoo and had similar chambers built for premature babies at a Paris maternity hospital. His colleague Dr. Pierre Budin began publishing results showing these warm-air chambers saved lives. In 1896, Dr. Martin Couney exhibited the Tarnier incubators at the World Exposition in Berlin, and all six premature babies on display survived. Couney eventually brought the concept to the United States, setting up a permanent exhibit at Coney Island amusement park where visitors paid 25 cents to see the tiny infants. For decades, this sideshow was one of the only places American families could access incubator care for their premature newborns.
Laboratory Incubators for Cell and Microbiology Work
In research and clinical laboratories, incubators are temperature-controlled chambers used to grow bacteria, fungi, and human or animal cells under tightly regulated conditions. The specific settings depend on what’s being grown.
For mammalian cell cultures, the standard is a CO2 incubator set to 37 °C (98.6 °F), which matches normal human body temperature. These units pump in a precise 5% concentration of carbon dioxide gas, which interacts with sodium bicarbonate in the growth medium to hold pH at a neutral 7.4, the same as human blood. Humidity inside is kept above 90% to prevent the liquid culture medium from evaporating. After something as brief as a 30-second door opening, a well-designed CO2 incubator recovers to within 98% of its target temperature, humidity, and gas levels.
There are two broad categories. Humid CO2 incubators offer precise atmospheric control and are the standard for most cell culture work. Dry incubators lack that level of control, so cultures must be sealed in airtight flasks to prevent evaporation. Placing a water dish inside a dry incubator adds some moisture, but it’s a rough workaround rather than a reliable solution. Specialized shaking incubators add constant gentle agitation, which helps scale up certain types of cell growth by keeping cells suspended evenly in liquid medium.
Egg Incubators for Hatching
Egg incubators replicate the warmth and conditions a brooding hen provides. For chicken eggs, the target temperature is 100.5 °F (38 °C), with an acceptable range of 99 to 102 °F. Humidity is also controlled, typically around 45 to 55% for most of the incubation period and raised higher in the final days before hatching.
Turning is critical. A hen naturally rotates her eggs throughout the day, and an incubator must do the same to prevent the developing embryo from sticking to the shell membrane. Eggs need turning at least three times a day, and five times is better. On day 18 of the 21-day incubation cycle, you stop turning and position each egg with the larger end facing up so the chick can orient itself properly for hatching. Home incubators range from simple styrofoam boxes with a heating element and manual turning to fully automated units with motorized egg trays and digital temperature and humidity displays.
Business Incubators for Startups
A business incubator is an organization that helps very early-stage entrepreneurs turn an idea into a functioning company. Unlike accelerators, which work with startups that already have a product and a tested business model, incubators accept founders who may have nothing more than a high-potential concept and a market opportunity. You don’t need a minimum viable product to apply.
The support typically includes mentorship, legal consultations, networking opportunities, and sometimes physical office space. Some incubators provide seed capital, though they are generally less likely to do so than accelerators. Both types of programs are selective and often take 5 to 10% equity in exchange for their services.
The biggest structural difference is time. Accelerator programs run as intensive, cohort-based bootcamps lasting two to six months. Incubators operate on a much longer timeline, typically one to five years, and some offer resources with no set expiration date. That extended runway makes sense given their mission: they’re working with founders at an earlier, less defined stage who need more time to develop, test, and refine before they’re ready to scale.
What All Incubators Share
Whether the goal is keeping a premature baby alive, growing cells for cancer research, hatching a clutch of eggs, or launching a tech startup, every incubator works on the same principle. It creates a protected environment with carefully controlled conditions, shields its occupant from threats it isn’t yet equipped to handle, and gives it time to develop enough strength to survive on its own.