Although Heat Stress is more widely known about in dogs, we rarely hear anything about Heat Stress in guinea pigs, and in fact, these animals are far more susceptible to heat stress than many other companion animals.
Native to South America, guinea pigs live in burrows and crevices, and have a preferred ambient temperature of 18 to 26 degrees. They are very sensitive to extreme heat and humidity, and are very susceptible to hyperthermia (high body temperature). In fact they are far more able to tolerate cooler temperatures than a warmer climate. Guinea pigs are so susceptible to heat stress that hyperthermia can even occur at temperatures as low as 24 degrees, but it is most commonly seen at temperatures above 28.
Heat Stress usually occurs during high temperatures or humidity, where there is inadequate shade and ventilation in the hutch, and often affects guinea pigs that are overweight or heavily furred.