Evaporative cooling only works in low humidity environments, in which sweating is also effective, and raise the indoor relative humidity to 100%. Also you need

Evaporative cooling only works in low humidity environments, in which sweating is also effective, and raise the indoor relative humidity to 100%. Also you need water and lots of it, the more water you can evaporate the better. Evaporative coolers IMO are less effective than open ventilation and shade.