Good point well made.
I took a trail lesson yesterday with a bloke who would have liked to have brought his wife and son. I had to disappoint them and only brought the son. Even then the pa28 was gasping for breath. If you are carrying people in the back seat of these 4 seaters, ALWAYS check the W&B, regardless of the temp. Its good airmanship.
Lets not forget the landing part too! No wind + hot temps = looooonger than expected touchdown point.