Can you explain what type of cichlids are in the tank and how the tank is setup? 35C is hot, but many cichlids can handle this temperature if they have adequate oxygen.
I suspect your fish are actually suffocating and not dying specifically because of the temperature. At this temperature, water has almost no ability to hold oxygen. Make sure there is ample surface agitation, limit stocking, run a good airstone, and do not use CO2. This is almost compulsory keeping tanks even at 32C.
If your humidity is low, you can use a fan across the water surface which will cool the tank by evaporation. This is actually very effective if there is enough airflow, but the humidity around the tank needs to be low, and it will require you to frequently top off the tank due to evaporative losses. If you live in a very humid area, this is usually a waste of time because you cannot get enough evaporation needed to effectively remove heat from the water.
Other than evaporative cooling, you're basically at getting a commercial chiller. For this size tank there's not really any other option that is reasonably effective at keeping it cool.