When most people think of sinus infections, they usually associate them with cold weather. However, sinus infections can occur at any time of year, including summer. During the warmer months, allergens such as pollen, dust, and mold spores are more active and can trigger sinus problems. Add in air conditioning, swimming in chlorinated pools, or traveling by air, and your sinuses can become irritated or infected in several ways. Understanding the signs of a sinus ...