Hi. Thankyou both for your replies. I also emailed the company that make my Acidophilus (Quest), and they've just got back with the following ...
"We say on the label that it has to be refrigerated just in order to be
cautious that people to do not leave it under direct light or heat for
example by a radiator or stove as too much heat can kill the good
bacteria in the capsule. However you can put them in room temperature,
such a dry cupboard away from direct heat and sunlight. If this is your
case then you will not need to buy a new batch."
This is from a nutritionist at Quest. I might just get some more to be on the safe side though.