This is a dumb question, yes, but I want to make this question unironically. So could a person on Mars make a dump on it? Like, literally make a shit on Martian soil, in the open.
If the astronaut just had a breather, it could breath normally; While only showing the butt to defecate as soon as posible. The low temperature would impact the astronaut (butt), yes, but if people can shit on the Earth Poles, they will there.
Now, about the low pressure of Mars atmosphere...would impact the human body that much, at least for a moment?