Well, day 1 was relatively uneventful. I wore it as an undershirt at work all day. The next morning, I proceeded to mow the lawn and go to the salvage yard (2 hours in hot sun with a thousand reflections) and even after sweating off 2 or 3 pounds of weight, it didn't smell. Day 3, worn to work, still no smell. Day 4, a slight funk. Day 5, hand washed it in the sink with a bit of laundry soap and let it hang dry. As long as you treat it gently, it will last for about 10 days. If you are going to be out in the sun a lot, be sure to give it a wash of some sort every 5 days. Next step is to order the underwear and try something similar with it.