Minnesota is the Land of 10,000 Lakes, but right now, only 9,999 are fit to swim in after a warning was just posted about staying out of this toxic lake. The hot, humid summer weather that’s been prevalent across the North Star State this July might make you want to take a dip on one of our 10,000 lakes to cool off, right? But local officials in this Minnesota city are urging you to avoid any contact with this lake that’s now unsafe.