Water is an important nutrient for pork production. Of the different classes of swine, lactating sows require the largest amount of water per day to boost voluntary feed intake and support adequate milk production, which directly influence litter performance. A major goal in the farrowing barn is to increase feed intake so as to boost milk production, prevent excessive sow body weight loss and achieve prompt return to estrus after weaning. High temperatures in the farrowing barn may lead to heat stress in sows, which can reduce feed intake and milk yield, reduce litter performance, and increase weaning to estrus interval. Results of a recent Korean study suggest that feeding chilled water (~15°C) to lactating sows housed in a high temperature environment may improve sow and litter performance. However, the energy required to chill the water should be considered in assessing the suitability of this approach.