Fine. I will assume you are a 13 year old girl with a nephew who put up a thread about how your dogs ate your fish for the sake of sympathy. Troll or not, you do bring up a good point. Very few people know how easy it can be to do temperature and water acclimation inside a fish bag. Below is the way I transported, acclimated, and re-tanked my fish when I was a college student.
I've used bags for my fish when I was traveling back and forwards from CT to NY when I was living on campus. Since I couldn't set up a fish tank before unloading a car, I would prop my fish bags up in a container and untie the top. The container doesn't have to be fancy. Once I used Dixie cups because I had two males and I didn't want them stressing each other out while I was getting my crap out of the trunk. The fish stayed safe in their bags with fresh air while I was trying to find which box held their tanks.
Once the tank(or tanks depending on the year) was set up, I would float the fish bag in the tank. The tank and the bag will raise to the same temperature together eliminating the water temp difference. Also, it returns the fish's water to a healthy temp as soon as possible. If the tank water is very cold, then turn on the heater and float the fish bag once the bag and the tank are the same temp. You can find small thermometers at Petco for $1.99. One goes in the tank and the other is dropped into the bag so you don't have to guess. I think $3.98 is worth it to avoid illness due to themp shock.
Once the tank and the bag are the same temp, then I would acclimate the fish to the water. I would fill the bag with 2 cups of water for a 2 hour trip. So at this step I would take 2 cups of water from the tank and add it to the bag. At this point the bag is a little full, so I just hold it in the tank until I know the water has mixed (since this point makes the fish swim around like mad). I dump enough out to re-tie the bag and let it flaot again. After about 30 minutes or so, the fish should be able to go into the tank without much stress.
I don't know how much this will help Lchurch7 if she doesn't use bags regularly. But it should help anyone else who is searching for fish travel tips. I know it took me a few trips between home and campus before I get the hang of it. XD