Chickens And Heat Stress

Summer’s no joke to chickens who need to keep their cool.

by Lisa Munniksma
PHOTO: Tim Miller/Flickr

A coop full of chickens laying down, spreading their wings and panting is a coop full of chickens suffering from heat stress. Just like you need a break from summer’s heat and humidity, so do your birds. Walking in and finding this situation leaves farmers with a somewhat helpless feeling, but you can work toward keeping chickens cool and reduce heat stress if you understand their physiology and are willing to adapt your chicken-keeping ways as the seasons dictate.

How Chickens Cool Themselves

While our normal body temperature is 98.6 degrees F, chickens run hotter—104 to 107 degrees F. Chickens can actually handle warmer temperatures than we can because of this difference. Humans sweat to cool themselves, but chickens don’t have the same means of keeping cool. Instead, they pant, evaporating moisture through their breath. They need to drink a lot of water to keep up their cooling system and reduce the chance of heat stress setting in.

Signs Of Heat Stress

Heat stress begins and chickens need help keeping cool when the ambient temperature climbs above 80 degrees F, and it is readily apparent above 85 degrees F, according to North Carolina Cooperative Extension Service. For most areas of the U.S., these are pretty normal summer temperatures.

Mild signs of heat stress in chickens manifest as:

  • reduced egg laying
  • lower hatching rates
  • reduced weight gain
  • smaller and weaker eggs
  • pale combs and wattles

Just as people become more irritable when hot and uncomfortable, chickens suffering from heat stress are also not themselves. They’ll be lethargic, eat less and drink more. More drinking leads to diarrhea. Chickens might be more likely to pick fights and engage in cannibalism, too. At its most severe, heat stress can lead to seizures and death.

Heat-Stress-Management Techniques

Keeping chickens cool is a big part of warm-weather poultry management. There are several heat-stress-management techniques that you can use as part of your chicken-keeping routine:

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Provide Continuous Access To Clean Water

When possible, add ice cubes to your chickens’ water source, or freeze a jug of water and submerge it in their water source to keep your chickens’ water cool.

Add Electrolytes To Drinking Water

Electrolytes—minerals found in the blood—regulate nerve and muscle function, and they include sodium, potassium, calcium, magnesium, chlorine, bicarbonate and sulfate. Added to the chickens’ drinking water, electrolytes help replace these minerals that are lost during heat stress through panting and diarrhea. They also make chickens want to drink more water, further keeping the chickens cool. The Texas Agricultural Extension Service recommends not giving electrolytes to chickens for more than 10 days at a time.

Ventilate The Coop

Especially if your chickens don’t have access to the outdoors, they need to have air movement. Sometimes cross ventilation with windows will help keep chickens cool; you may need to provide a fan at other times.

Provide A Mister

A mist of water along with ventilation will help to keep chickens cool. Don’t soak the chickens, rather provide enough moisture so it can evaporate and help cool the birds.

Offer Shade

Chickens need a place to rest in the shade if they’re outdoors. You’ll find chickens manage heat stress on their own by seeking shade during the hottest part of the day.

Change The Feeding Schedule

The University of Wisconsin Extension suggests keeping chickens cool with an amended feeding schedule. Eating—or, more accurately, digestion—creates heat in the body and adds to heat stress. A late-afternoon or evening feeding time will allow most digestion to take place overnight, when temperatures are cooler. This may encourage chickens to eat more during warm weather, helping to maintain their egg production and weight gain.

Homemade Electrolytes

There are multiple recipes online and in books for making your own electrolytes to add to your chickens’ water to help ward off heat stress. Two homemade electrolyte recipes are below. Consult with your veterinarian before giving your chickens a homemade electrolyte supplement to be sure it’s appropriate for your flock during periods of heat stress.

Simple Electrolyte Recipe



  • 1 cup water
  • 2 tsp. sugar
  • 1/8 tsp. salt
  • 1/8 tsp. baking soda


Mix all ingredients together, and add to 1 gallon of water.

Sweet Electrolyte Recipe

via Our Little Coop


  • 1¼ tsp. unrefined sea salt
  • 1 tsp. baking soda
  • 1/2 tsp. potassium chloride salt substitute
  • 2 T. honey or molasses


Mix all ingredients with 1/2 gallon of water. Do not keep more than 24 hours.

Heat-Tolerant Chicken Breeds

Just as there are some breeds of chickens equipped to produce a lot of eggs and some that have been bred for meat production, there are some chicken breeds that have heat tolerance. If you live in a warm climate or if you experience serious summertime heat and humidity, having the right chicken breed can reduce incidence of heat stress in your flock. Consider these heat-tolerant chicken breeds:

  • Leghorn: A common layer breed, Leghorn chickens have a commercially developed strain and a heritage strain. They lay 150 to 300 large, white eggs each year, and they are hardy free-range birds. Leghorns can be found in a variety of colors with a range of comb types.
  • New Hampshire: A dual-purpose chicken, New Hampshires mature early and lay large, light- to medium-brown eggs. They do well in the heat and the cold, but they may get frostbite on their combs. They are larger than but similar to the popular Rhode Island Red chickens, as they were developed from the Rhode Island Red breed.
  • Rhode Island Red: This popular breed is found on small-scale farms across the country. Rhode Island Red chickens mature early and lay 200 to 300 large, brown eggs each year, even in less-than-ideal conditions. There is a heritage strain and an industrial strain of this breed.
  • Silkie: The Silkie’s fur-like feathers and black skin make it a novel hit among backyard chicken keepers. This is a bantam breed—hens weigh only 2 pounds, and roosters not much more than that—that is found in a variety of colors. Their small eggs have a tint of color to them. They do well in heat and in cold, but their feathering makes them unsuitable for outdoor living in inclement weather.

The hot summer months offer new challenges to raising animals of any kind. Help your chickens through periods of heat stress by knowing the signs of heat stress, keeping your chickens cool and selecting the right breeds for your flock.

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