A heat wave won't make most pantry foods unsafe, but it can cause some staples to spoil faster.Reviewed by Dietitian Emily Lachtrupp, M.S., RDCredit: Design elements: Getty Images. EatingWell design.Key PointsHeat can speed up oxidation, causing fats to develop off-flavors.Oils, nuts and natural nut butters stay fresher when refrigerated.Whole-grain flours and bread need extra care during extreme heat.When a heat wave is in the forecast, you'll …