This is actually a very debated topic among English-speaking Esperanto speakers, because "warm" and "hot" can mean different things in English depending on the context. Take these examples:
hot soup / warm soup
hot coffee / warm coffee
hot shower / warm shower
hot room / warm room
varma (hot) is actually the direct opposite of malvarma (cold), so varmeta is more like warm and varmega is more like scalding hot. Since these meanings are so fluid, we often accept both translations for each word, because it often depends on personal interpretation how someone would personally translate the degree of varma into English depending on the context.