Medical co-director of the Twin Cities Marathon, Jacob Kastner, says there's science to it.

Generally speaking, you know, running and marathon running for distances puts a lot of work and stress on the body, and there's a lot of different organ systems that are working in tandem when we're running.

Uh, internal organ systems, your muscles, your cooling effects, your skin, everything like that.

So it's already generating a lot of heat in the body, which puts stress on your muscles and on your skin and, and you have to have a good ability to cool.

Yes, it gets uncomfortable, but it's a lot better than the alternative, as Jacob Kastner says.

When we run in the heat, things change, and it becomes more difficult for your body to cool and can increase your risk of organ problems.

Things that can happen is your core temperature rises in your body.

It puts more stress.