My relative rents an apartment with an old gas stove. Even when off, it radiates heat and is being told that the heat is caused by the pilot light. This is making it difficult to cool the apartment during the summer. Could this be true, and if not the cause, what do you think the issue is? Could the pilot light need to be adjusted?
As Ed Beal mentioned in a comment, something doesn't sound right here. I have a gas range as well, and it's getting over 90* F here lately. I don't have a steamy kitchen. I'd have an appliance tech look at the pilot to see whether it's far too large.
It can be true, the pilot light is there to assure that there is no un-combusted gas leaking out of the system, and to start the system when necessary. It's as much safety as utility. There are probably no adjustments required, it's meant to always be on. You should feel warmth, but it shouldn't be 'hot' in the stove.
-edited- as I was thinking it was this kind of stove.