When you get your tomatoes home, you certainly can refrigerate them. But, if you will please notice, when you buy them in the grocery store, they are warm. I have worked for almost 15 years in the grocery industry and I can tell you that produce managers (at least good ones) do not refrigerate tomatoes. When refrigerated, they become mealy and lose flavor. As a former Deli manager, I purchased flats of tomatoes several times per week and, although they were transported in a refrigerated truck because it was not feasible for the produce company to make two separate deliveries, one refrigerated, one not, we were told to store the tomatoes at room temp. The flats of tomatoes were the last thing loaded onto the truck and the first thing off to minimize the chilling. Once the tomatoes were SLICED for sandwiches, they were refrigerated... and used within about 6 hours.
Prior to my life in the grocery industry, I worked for a plant geneticist on a research farm in Oregon. One of his major projects was developing several tomato cultivars (there is one on the market now called "Oregon Spring") and it is from him that I first learned (thirty years ago!) that tomatoes should not be refrigerated.
If you're buying crappy, mealy tomatoes in the grocery store right now, you probably can't do them much harm by sticking them in the refrigerator. But during the summer, when a lot of us love to grow our own, why ruin the wonderful flavor, aroma and juiciness by sticking them in the fridge?
I'm not going to post a bunch of links here to prove my point, but all you have to do is Google "refrigerate tomatoes" and you will find PAGES of links telling you why you should not refrigerate them.
My best suggestion if you like them cold in salads and sandwiches: store them at room temp, then an hour before you want to use one, toss it in a cold spot in the fridge to cool down. Best of both worlds.