Heat stress in farm animals is increasing in frequency and severity as global temperatures rise. Monitoring, prevention and emergency response protocols are welfare-essential on farms in warming climates.
Heat stress welfare is both immediate and cumulative. Acutely, animals in severe heat stress experience hyperthermia, respiratory distress, weakness and cardiovascular collapse. Chronically, periods of moderate heat stress reduce immunity, reproductive performance and growth without obvious clinical signs - a welfare cost that is borne invisibly. Climate change projections suggest that heat stress events that currently occur rarely in UK agriculture will become annual and then frequent occurrences. Planning for heat stress management - shade provision, cooling systems, water adequacy - is welfare planning for a near-term reality rather than a distant risk.