Will a power outage ruin my hatching eggs?

**Usually not.** Embryos tolerate cooling far better than overheating and have survived below 90°F for up to ~18 hours. Keep the incubator closed and insulated, wait for power to return, and candle 4–6 days later — most hatches survive a multi-hour outage, though they may run a day or two late.

Should I open the incubator during a power outage?

**No.** Opening it releases the warm, humid air protecting the eggs. Keep it closed, insulate it with blankets or a box, and add sealed jugs of warm water for heat storage instead.

How long can eggs survive without power in the incubator?

It depends on how cold the cabinet gets, the age of the embryos, and humidity, but embryos have survived below **90°F for up to roughly 18 hours** (Penn State Extension). A shorter outage of a few hours typically only delays the hatch rather than ending it.

Is cold or heat worse for incubating eggs?

**Heat is far worse.** Mississippi State Extension notes a brief spike near 105°F for even 15 minutes can seriously harm embryos, while ~95°F for 3–4 hours only slows them down. That's why a power outage — which cools the incubator — is usually survivable, and why you should never overheat to 'catch up' afterward.

How do I keep the incubator warm without electricity?

Insulate it with blankets, towels, or a cardboard box; add sealed jugs of warm (not hot) water for thermal mass; and, if needed, tuck chemical hand warmers near — but not touching — the eggs. Keep the lid closed the whole time.

My eggs got cold — will the hatch just be late?

Often, yes. A cool spell slows embryo development, so a hatch can run **a day or two late**. Give day-21 chicken eggs until day 22–23. Candle 4–6 days after power returns to confirm which eggs are still developing before giving up on any.

Power Outage During Incubation: How to Save the Hatch

Verified September 2026

The short version

Don't panic and don't open the incubator. Developing embryos tolerate a cool spell far better than overheating, and many hatches survive a multi-hour outage. Keep the lid closed to trap heat, insulate the incubator with blankets or a cardboard box, and add sealed jugs of warm water for thermal mass. Embryos have survived below 90°F for up to ~18 hours, so keep them as warm as you can and wait — then candle 4–6 days later to see who's still developing. Your hatch may simply run a day or two late.

Why a cool spell is survivable — and why you must NOT open the lid

Extension guidance is reassuring here: overheating is far more dangerous than cooling. Mississippi State University Extension notes that a brief spike — running an incubator around 105°F for even 15 minutes — can seriously damage embryos, whereas holding around 95°F for 3–4 hours merely slows their metabolism. That asymmetry is why a power outage, which makes the incubator go *cold*, is usually recoverable. Penn State Extension reports embryos have survived below 90°F for up to roughly 18 hours, so a typical outage rarely means a total loss.

The single most important thing you can do is keep the incubator closed. Every time you lift the lid you dump the warm, humid air that's protecting the eggs. After about the first two weeks the embryos are big enough to generate their own metabolic heat, so a sealed, insulated incubator will actually hold warmth for a surprisingly long time — but only if you leave it shut. Resist the urge to peek.

Holding heat without power: insulate, add thermal mass, and improvise a heat source

Work fast but calmly. Insulate the whole unit by draping blankets or towels over it, or dropping a large cardboard box over the top — trapped air is an excellent insulator and slows how quickly the cabinet cools. Add thermal mass: seal several jugs or bottles of warm (not hot) tap water and tuck them inside or right against the incubator. Water stores heat extremely well and releases it slowly, smoothing out the temperature drop for hours.

For a low-tech heat source, chemical hand warmers (the air-activated kind) can be tucked under the insulating box near — but never touching — the eggs to add gentle warmth without electricity. Some hatchers place candles in glass jars under the covering box; if you do, treat open flame with extreme caution, keep it well away from bedding and blankets, and never leave it unattended. Aim only to keep the eggs from getting cold, not to hit the exact incubation setpoint of 99.5–100°F — a mild cool spell is fine, and gentle is safer than a burst of overheating.

After the power returns: restart, wait, and candle for survivors

Once power is back, remove the water jugs and warmers, close the incubator, and let it climb back to the normal setpoint (99.5–100°F forced-air) and humidity on its own. Don't crank the temperature above the setpoint to 'catch up' — that's exactly the overheating that kills embryos. Then be patient. A cool period slows development, so the hatch may run a day or two late; give day-21 chicken eggs until day 22–23 before worrying.

Don't scrap eggs based on the outage alone. Candle roughly 4–6 days after the power is restored: living embryos will show continued vein growth, movement, and a drawn-down air cell, while quitters will look dark, cloudy, or show a blood ring. Pull only the eggs that are clearly dead so they don't spoil, and let the survivors ride out to hatch. To prevent a repeat, put the incubator on a battery backup (UPS) or arrange a generator for the next hatch — a small UPS can bridge short outages entirely, and a generator covers longer ones.

Common pitfalls

Opening the incubator to 'check on' the eggs — this vents the warm, humid air that's keeping them alive. Leave it shut.
Overcompensating by raising the temperature above the setpoint after power returns. Overheating kills embryos far faster than a cool spell does.
Throwing eggs out too soon. Wait and candle 4–6 days later before deciding anything is dead.
Using hot (not warm) water or letting a heat source touch the eggs, creating a hot spot. Warm, gentle, and indirect is the rule.
Having no backup plan — no UPS or generator — so the next outage repeats the emergency.

Frequently asked questions

Will a power outage ruin my hatching eggs?: Usually not. Embryos tolerate cooling far better than overheating and have survived below 90°F for up to ~18 hours. Keep the incubator closed and insulated, wait for power to return, and candle 4–6 days later — most hatches survive a multi-hour outage, though they may run a day or two late.
Should I open the incubator during a power outage?: No. Opening it releases the warm, humid air protecting the eggs. Keep it closed, insulate it with blankets or a box, and add sealed jugs of warm water for heat storage instead.
How long can eggs survive without power in the incubator?: It depends on how cold the cabinet gets, the age of the embryos, and humidity, but embryos have survived below 90°F for up to roughly 18 hours (Penn State Extension). A shorter outage of a few hours typically only delays the hatch rather than ending it.
Is cold or heat worse for incubating eggs?: Heat is far worse. Mississippi State Extension notes a brief spike near 105°F for even 15 minutes can seriously harm embryos, while ~95°F for 3–4 hours only slows them down. That's why a power outage — which cools the incubator — is usually survivable, and why you should never overheat to 'catch up' afterward.
How do I keep the incubator warm without electricity?: Insulate it with blankets, towels, or a cardboard box; add sealed jugs of warm (not hot) water for thermal mass; and, if needed, tuck chemical hand warmers near — but not touching — the eggs. Keep the lid closed the whole time.
My eggs got cold — will the hatch just be late?: Often, yes. A cool spell slows embryo development, so a hatch can run a day or two late. Give day-21 chicken eggs until day 22–23. Candle 4–6 days after power returns to confirm which eggs are still developing before giving up on any.

Sources

In Case of Power Outage (Embryology / incubation) — Penn State Extension (University extension)
Trouble-Shooting Failures with Egg Incubation (overheating vs. cooling) — Mississippi State University Extension Service (University extension)
What Happens if the Power Goes Off During Incubation? — Brinsea (incubator manufacturer) (Manufacturer manual)