It is called hard work outside under the sun in summertime. I take it you have an office job.
I've had plenty of jobs over the years, from construction to hazardous waste to computer tech. I've worked in West Texas in the summer in a tyvek suit, and I've sweated so much that I had to stop every so often to pour the sweat out of my rubber boots and rubber gloves.
The only way that I can think of for money to get all wet and sweaty is if somebody put their money in the bottom of their shoe while they were working. I prefer to keep my money in my pockets, not my socks. But, hey, power to you.