I always warm the fluids to body temperature. I put the bag against my arm and if I can feel a temperature difference between it and my skin, it's not warm enough (or if it feels hot to me it's too warm.)
It can take quite a while to warm them up, and I also make sure to swish the bag around while warming so the fluid warms all the way through. I have found that getting them warmed enough makes a big difference. Some of the pets I've given warm fluids to objected a bit to the actual needle going in but none of them objected to the body-temp fluids going in.
I also tent the skin quite a bit and hold it up/tented (if they'll let me) for a short time after the fluids start flowing to help it spread under the skin better (this only works if you use two people though, otherwise you don't have an extra hand to hold the skin tented.)
It can take quite a while to warm them up, and I also make sure to swish the bag around while warming so the fluid warms all the way through. I have found that getting them warmed enough makes a big difference. Some of the pets I've given warm fluids to objected a bit to the actual needle going in but none of them objected to the body-temp fluids going in.
I also tent the skin quite a bit and hold it up/tented (if they'll let me) for a short time after the fluids start flowing to help it spread under the skin better (this only works if you use two people though, otherwise you don't have an extra hand to hold the skin tented.)