During the chilled winter months, there’s a heat-seeking tendency in all of us. Hot tubs are not just associated with relaxation, post-gym therapy and socializing, but bacteria and waterborne diseases too. That is, not all hot tubs pose a health risk, but it is important to know when not to climb into a hot tub.

Expert Jonathan Yoder, an epidemiologist at the Centers for Disease Control and Prevention, reveals some pointers of when to steer clear:

Hot tubs are usually around 104 degrees or less — not enough to kill bacteria that thrive in heat. However, most of these bacteria will remain inactive if you maintain a proper method of disinfection. That is, make sure to take a shower or cleanse yourself post-hot tubbing.

Hot tubs are also supposed to be cleaned, go through proper maintenance checks and have its filter cleaned on a pretty orderly basis. Use your best judgment to scan the hot tub for clear proof of cleaning. If the jacuzzi looks in any way dirty or unsanitary with grimy tiles, etc. best you don’t go in!