I work at a pet grooming salon and we’ve endured one for the hottest summers on record with zero A/C. What are my options to get the message across that we’re fed up?

This is in NY if anyone's curious. We're all sick and fed up about it. It's been absurdly hot and we have equipment blowing hot air for upwards of 8 hours a day or more in a very small environment. We're not even supplied fans for some kind of relief. Their answer has more or less been “just deal with it” because the boss owns 5+ businesses and isn't even here most of the time to care about it. Even the animals are visibly suffering, customers complain when they walk in and the landlord of the property (not the owner of the shop) is a typical jerkoff NYC landlord who does nothing, but I feel like if we pressure the boss then he'll have no choice but to cause a stink with the landlord.

Any ideas on how we can get even a basic amenity like this going when conversation has lead to nothing but dead-ends?