Salutations PGodin...
Don't quite know your setup...if both sump and canopy closed, some fans a must, and may be all you need living in NE...
I did same, adding 4 large size (quiet) computer fans which I have hooked up to a thermostat. - cools off temp in a hurry when needed.
Living in PNW, really high temperatures not all that common...but when they do occur, I would rather opt for a room air-conditioner rather then a tank chiller. Much cheaper, and keeps me "comfortable" also...
Does sound like you guys over there having an unusual heat wave...Maybe something we are all going to have to start making allowances for.
Good luck,
OmarD