We need a little bit more information on your design to answer your questions.
Is your dependent variable similar between the 2 conditions (e.g., you measure speed on a certain task when participants are in a cold room and when they are in a warm room)?
Is your dependent variable at interval, ordinal, nominal?
Is dependent variable normally distributed?
In any case, you could search for "within subject 2 measures" to get some ideas about where you should go, if you need more help please provide more details.