There was a fun seminar with a guest speaker once upon a time when I was in graduate school where he put the physiological effects of stress into perspective. I can't remember his name now, but the gist was that if you imagine yourself as an animal fighting for survival, you are very likely to want to keep the body ramped up to run or fight rather than to fight infection, digest, or reproduce. In a human context, when the person is under pressure due to a huge work project or some other external force derived from a crushing mountain of responsibility, they are thrust into a situation where the body and mind think that they are in a "fight or flight" mode and that can lead to many physical and psychological detriments. Although what we do in science is important and requires lots of work, it is important to realize that good science is harder to do if we are overcome with stress, so let's find some ways to manage stress so we can be more productive and healthy.