A hothouse is a heated building, usually made of glass, in which plants and flowers can be grown.
N-COUNT
（尤指思想或感情活动的）爆发地，温床
You can refer to a situation or place as a hothouse when there is intense activity, especially intellectual or emotional activity.
例句
The vast crowds make Rome a frantic hothouse at times.熙攘的人群有时将罗马变成一个癫狂情绪的爆发地。...the reputation of the College as a hothouse of novel ideas.该学院享有的新思想摇篮的美誉