Sheep are often assumed to be adapted to heat, yet thermal stress causes significant welfare harm in many breeds and management systems. Providing appropriate shade and ventilation substantially improves summer welfare.
Sheep thermal welfare is frequently underestimated because sheep are associated with cold, wet climates and are assumed to be resistant to heat. In reality, many sheep breeds — particularly those carrying heavy wool — experience significant heat stress in summer conditions across temperate and warm climates. The physiological impact of heat stress in sheep is real and measurable: elevated core body temperature, increased respiratory rate, reduced feed intake, and impaired immune function all indicate welfare compromise. The practical welfare interventions are straightforward: shade provision, whether through planted trees, temporary shade structures, or modified grazing management that provides access to shaded areas during the hottest parts of the day, significantly reduces core body temperature and behavioral heat stress indicators. Timely shearing before the onset of summer heat removes the primary physical cause of heat stress in wooled breeds. Water availability in adequate supply and accessible location is critical — heat-stressed sheep require far more water than cool-weather sheep, and inadequate water during hot periods represents an acute welfare emergency. Breed selection in warm climates for natural wool shedding or heat-adaptive traits represents a long-term welfare solution that reduces management demands while improving individual welfare outcomes.