It is in these conditions: RD giving you "the eyes" causes you to turn into a bowl of ice cream. Rarity will refuse to enter the pool. Pinkie will rapidly dunk you in the water. Pinkimenia will rapidly stab you in the water. Fluttershy will have 300 floatation devices because she's afraid of drowning.
Twilight will awkwardly try to start a conversation about the heat, but fail. Then you two will sit in the pool in an awkward silence. AJ will try to start a conversation about the heat, then talk about it for hours as you get bored out of your mind.