"It is hot tea."
I'm pretty certain both can... are you sure the sentences were the same? Because there is a difference between "this tea is hot" and "this is hot tea".
This tea is hot: このおちゃはあついです
This is hot tea: これはあついおちゃです
It is hot tea: あついおちゃです
Both あつい and つめたい don't change when you put them in front of the noun because they are i-adjectives. For na/no adjectives you have to conjugate them, so the difference is clearer.
Not to steal your spotlight, but to make it easier to read
This tea is hot: この茶は暑いです
This is hot tea: これは暑い茶です
It is hot tea: 暑い茶です
暑い = あつい, hot.
The following things are also あつい, but not hot (in the correct sense)
熱い = Heated, passionate, zealous, intense, severe, hot (topic)
厚い = Thick, heavy, deep, cordial, kind, serious (of an illness)
篤い = Alternative kanji to previous.
茶 = ちゃ, Tea
おちゃ often refers to green tea, or gives reverence to the tea, such as tea served in a traditional ceremony. Also お茶 can be used for a tea break at work.
It helps to read the important particles and adjective suffixes (い) without muddling the meaning.
According to jisho.org, 熱い is used for hot things, which would include tea. I found this sentence on a Japanese site: 暑いけど熱いお茶飲むよ (あつい'けど'あつい'おちゃ'のむよ / It's hot (weather), but I'm drinking hot tea). Do a google search for both 熱いお茶 and 暑いお茶 and you'll see with the first one that you can find actual examples of the phrase coming up, while with the second one you will see a lot of results for hot days or hot summer, but not hot tea.
Those mark the subject/topic, which is omitted here. To say something "is noun" you just have to use noun+です. For example, "is student" would be "がくせいです", but if you wanted to make it clear who you were talking about you could say, for example, "[かのじょは]がくせいです" for "[she] is student". Usually the かのじょは part would be obvious from context, which is why it's often left out unless it's unclear.
In this example, maybe someone saw a cup on the table and asked "あれはなんですか" (what is that?). The full reply would be ”[あれは]おちゃです” ([that] is tea), but that's a little redundant since it's already clear what you're talking about, so the あれは part can be dropped and the reply could be just "おちゃです" (is tea), or more specifically, "あついおちゃです" (is hot tea). The あつい part just modifies the noun, and doesn't change the rest of the sentence structure.
Note that this is different than saying something like, "the tea is hot". In that case "tea" would be the topic/subject and you can say ”[おちゃが]あついです” ([tea] is hot). Or, if the context is clear, just "あついです" (is hot).
What is the difference between 熱い and 暖かい (あたたかい)?
Please correct me if I wrong, but I read somewhere before (I forgot where it was) that 熱い is only used to mean hot in "hot weather", while 暖かい is used to mean hot to the touch, like in "hot water". This is why I thought "It is hot tea" translates to 暖かいお茶です。
It is still in development. Some kanji are not accepted primarily because it has not been taught, but you are correct in the importance of kanji. If you are 100% certain that the sentence is correct and you didn't pick the wrong kanji, then report the answer as correct.
熱い is for when a thing is hot, such as tea.
暑い is for weather.
Crikey, first get cold as first word, then the next has the object in front of hot. Then with this one hot is in front again, just like cold.
Everytime I think i understand the grammar it turns it all upside down again.
Translating to english is easier, because English grammar is consistant.
You still would need a copula of some sort to be grammatically correct since you can't end a sentence on a noun.
Colloquially in speech it may be accepted as understood through context just as "It hot tea" would in English, but it wouldn't be 'correct'
If you wanted to be casual it would be 熱いお茶だ
This is one of those things where native speakers, like myself, don't even know the reason. We just know it doesn't sound right. It's interesting to see the explanation, and it does make sense. This is the difference between acquiring language, and learning language (which I hear is a distinction the linguist Stephen Krashen makes). I didn't learn English; I acquired it as a child. I then mastered it further through a combination of learning through school, and further acquisition by listening and reading in the subsequent years.
The difference here is that 熱いお茶 is two words; an adjective modifying a noun, "hot tea"
白ワイン is a compound noun treated as a single word, a specific type of wine "white wine"
Similar to how 緑茶・りょくちゃ "green tea" and 紅茶・こうちゃ "black tea" are types of tea and nouns you would find in a dictionary, not just adjectives describing tea