Fever is one of the most common clinical signs of infection and systemic inflammation and is an important component of non-specific acute phase response. However, its activation results in increased metabolic rate and energy expenditure with negative consequences on animal growth and feed efficiency. This study aimed at investigating the effect of repeated administrations of Escherichia coli lipopolysaccharide (LPS) on the internal temperature of growing pigs and its associated impact on metabolic heat production. In response to LPS, internal temperature of the animals increased from 38.7 to 40 °C within 150 to 200 min after the LPS administration. The corresponding increase in maintenance energy requirements was estimated in 100 kJ/kg BW0.60/d which is equivalent to 10% of the basal metabolic rate of growing pigs.