Does it need to be tossed out? It's been about 24 hours without refrigeration. Thanks.
I don't think so. Jams are loaded with sugars and can take quite a bit of abuse. I'd refrigerate it now, though.
I lived in England for 35 years and no-one I know keeps their jam in the fridge there. Occasionally my father scrapes a moldy bit off (if the jam is VERY old) and keep on using the jar. He is 82 and still going strong although I don't recommend his strategy myself!!