The first step in reducing the impact of heat stress on sow fertility is to make sure ventilation systems are in good working order and are providing adequate air movement. Minimum enclosed facility ventilation rates for a sow and litter, gestating sow, and breeding sow or boar during the summer months are 500, 180, and 300 CFMs/hd, respectively, however, these rates may be doubled during the summer months in the southeastern U.S.. Conduct a thorough maintenance inspection and test the ventilation system to ensure that these rates are met. It is not uncommon to find that (even in fairly new operations) ventilation systems do not operate as designed. Unless these systems are delivering the required ventilation rates, other management practices suggested here will not be effective. Additionally, fresh air must enter rooms at a speed of 600-1,000 ft/min. in order to circulate well and prevent cold air from falling on animals (drafts). Don't overlook the fresh air inlets; adjustments should be made seasonally. A good, year-round air-inlet-speed-goal is 900 ft/min.