What Should I Do If the Power Goes Out?

This is probably the second most frequently asked question I'm asked, after, "Why did my fully developed chicks die right at the end?"

The advice most people receive is to wrap the incubator in blankets, add hot water bottles, or somehow try to keep the eggs warm.

In many cases, especially during the first half of incubation, I believe this is the wrong approach.

The Dangerous Temperature Zone

For embryos between approximately Day 0 and Day 10, it is often far safer to allow the eggs to cool below about 25°C, where development effectively becomes dormant, than to try to hold them somewhere between 28°C and 35°C.

Why?

Because in that intermediate temperature range the embryo is still developing—but not normally.

The countless developmental processes taking place inside the egg are temperature dependent. When the temperature is well below the normal incubation temperature, those processes no longer remain properly synchronised. Development may continue, but the different systems are no longer keeping pace with one another.

In engineering terms, it is rather like running a complex machine with only half the mechanisms operating at the correct speed.

The result can be systemic failure.

Dormancy Is a Natural Survival Mechanism

Eggs are remarkably resilient.

In nature, a broody hen frequently leaves the nest to eat and drink. During that time the eggs cool considerably before warming again when she returns.

The developing embryo has evolved to tolerate these interruptions.

Cooling the egg is not immediately destructive. In fact, it is a natural survival mechanism.

As the egg cools, changes in its chemistry, including changes in pH, help preserve the contents and reduce the opportunity for bacterial invasion through the shell.

It takes considerably longer than many people imagine before chilling itself causes irreversible damage.

What About Older Embryos?

Although younger embryos tolerate cooling best, the same principle often applies to older eggs during surprisingly long power failures.

Many people assume that every minute without heat is catastrophic.

In reality, eggs are often far more tolerant than we give them credit for.

There are documented reports of commercial hatcheries experiencing prolonged power failures where generators were operated only during working hours and switched off overnight for several consecutive nights. Despite these interruptions, many eggs still hatched successfully.

The Practical Takeaway

If the power fails, resist the temptation to keep the eggs only partly warm.

For young embryos, it is generally safer to allow them to cool into dormancy than to maintain them in a temperature range where abnormal development can continue.

Sometimes the best thing you can do is... nothing.

That advice may seem counterintuitive, but understanding how embryos respond to temperature is often more important than simply trying to keep them warm at all costs.

Written by Bob Peel, Greatlander