noun which may take the genitive case particle 'no', na-adjective, noun
relatively hot; fairly hot; on the hot side
Describes something that is somewhat hotter than usual or hotter than expected. Often used for food, drinks, or weather.
今日はいつもより熱めのお風呂に入りたい。
Today I want to take a bath that's a bit hotter than usual.
このスープは熱めでおいしい。
This soup is delicious when it's fairly hot.
熱い means 'hot' in an absolute sense, while 熱め means 'relatively hot' or 'on the hot side'.
Formed from the stem of 熱い (あつい, 'hot') + the suffix め, which indicates a tendency or degree ('somewhat', 'on the ~ side').