Summer temperatures make livestock transport particularly dangerous. Heat stress during transit causes suffering, injury, and mortality that are largely preventable through timing, vehicle design, and load limits.
Summer livestock transport combines multiple simultaneous welfare challenges: metabolic heat from animal bodies, solar radiation heating vehicles, limited ventilation in many designs, and physiological stress from movement and noise. Pigs are most vulnerable — they cannot thermoregulate effectively and heat stress escalates rapidly. Mortality from heat stress is the most visible welfare failure, but prolonged thermal discomfort short of death is equally significant. Timing, vehicle ventilation standards, and pre-journey heat assessment can substantially reduce heat stress mortality and suffering.