During hot weather plants need adequate water. This is pretty obvious.
It is important to water thoroughly each time so that the moisture reaches down to the subsoil where the roots can stay cool and take up water.
In the case of potted plants, make sure that the bottom of the root ball is moist. Watering thoroughly at each application should top up the moist potting mix at the base of the pot.
Many people give a little water each time so the top of the pot looks moist.
The trap here is that the bottom half of the mix is likely to be dry as it never receives enough water to infiltrate the volume of soil in the pot. The next thing you know is that the plant dies.
The other important factor often overlooked is that if you water thoroughly as you should but don’t provide any nutrient the plant will stay alive but without fertilizer it is like a human who is stuck in the desert with plenty of water but no food; it will survive grow weaker. The main thing is to avoid applying fertilizer in temperatures over 30 degrees C. Through our summer we have cooler periods in the mid 20’s. This is the time to fertilize. If using a granular fertilizer, make sure you water it in well to avoid burning.
By watering regularly but not too often you are training the plant to be more drought resistant. Every situation and every plant is different so there is no blanket rule. You just have to observe your plants. Generally if the plant looks healthy it may not need water. It is easier to revive a wilting plant than one that has been over watered. This particularly applies to indoor plants.