Good to hear that it isn't anything major, at the same time don't call it a day. These things aggravate over the period of time and end up with something else. My posture is bad too but DW is a physical therapist so she corrects me all the time. Bad posture can lead to weakening of muscles and lead to headaches (Possibly one of the cause with my migraine because my migraine starts from the neck).
You know what to do with stress, yoga, meditation etc.
Heat, take care from the heat. I HATE heat, anything about 70F triggers headache in me.
Posture, go to OT and fix it soon.
Oh, don't get me wrong, I'm not gonna just go back to the way everything was. I'm definitely going to look into the posture, I'm keeping hydrated, and stress is just because of exams in a week. I should also try and cut back on the TV and video games too, I doubt they're good for the eyes -> headaches. Strangely enough, this is the first time I've had a headache that's lasted this long. Maybe I usually keep more hydrated. Also, I'm spending more time at my computer, rather than on the couch, like I used to, so maybe my chair is bad. Anyway, cheers for the advice, I'm a bit of a hypochondriac, so I always like to find out what's up with me.