Summer flare-ups can be frustrating because they may seem to happen without warning. You may be following your usual routine, wearing your compression garment, staying active, and caring for your skin, yet still notice that swelling becomes worse during hot, humid weather. Heat waves, vacations, outdoor events, long car rides, air travel, increased sweating, sun exposure, salty foods, bug bites, and changes in activity can all affect how your body feels during the summer months.