I saw a question earlier about drying clothes in the sun vs. drying them in a high-heat dryer. If you are concerned about which method kills pathogens more, I would say that drying your clothes in the sun would indeed be more effective due to the presence of ultraviolet light. UV light is the primary reason that pathogens/bacteria do not survive well in sunlight. For example, molds often grow in dark and moist environments. If UV light and heat were introduced into those environments, mold growth would be significantly reduced, if not reversed. That is why you see many air purifiers and even toothbrush cleaners using UV light.