Not always ,,,warm saline  rinses can in some cases may increase the pain. If having warm liquid increases your pain and cold liquid helps in decreasing pain then your condition is most probably ( irreversible puliputis)  which suggest that u might be needing a root canal treatment in a tooth or teeth . But if there is some periodontal pocket or soft tissue injury in gums then warm saline rinses can help a bit . All the above conditions can't be generalised ,,so what exactly is happening in your case can't be told until examined properly .