Wouldn’t any liquid in your hand literally be starting to freeze at 30 F? I guess different solutions have different freezing points but isn’t cytoplasm still mostly composed of water? I measure how cold it is in the winter by how many seconds it takes for my snot to freeze. I don’t exactly live in the South, but I suppose I do live in a climate that’s more temperate than either New England or Montana. All that to say 30 F is cold.