What temperature should mammalian B-Cells be stored at outside of the incubator?

I'm working with murine B-cells. The general protocol is to keep cells on ice to keep them from dying but I've noticed that it makes these cells aggregate and precipitate out. I've heard suggestions that these cells should just be kept at room temperature. How would I be able to determine which conditions at which I should be keeping my cells?

I was trying to collect cells to prepare them for cell binding studies to antibodies and then assess the cells on a filterplate. Typically, you keep them on ice to pause the metabolic state as well as to prevent endocytosis of the bound molecules. However, that shift seems to cause settling. How do you troubleshoot the appropriate temperature to process cells and what are the usual scientific justification for making such decisions.