We eat a lot of Indian food and when we're at Indian restaurants, I tell them to make my food a 6 (on a scale of 1 - 10) and sometimes even a 5. It was a 7 when I was in my 20's and 30's, but my stomach won't take it anymore. Dh, who is in his 50's still gets 7 or 8. Dd (8yo) asks for level 3.
When I cook at home (my mother lives with us) foods are not made spicy hot at all because of her. Each person adds the amount of spice they want before eating. Even dd likes it spicier than my mom.
Interesting aside... we're multilingual/multicultural in our house. In every language spoken by one or more of us, there is a word for "spicy hot" and a word for "temperature hot". Only in English do we not have that... because spicy doesn't necessarily mean "hot" spicy in English. I make very spicy dishes, but the spices themselves may be very mild. Interesting observation, anyway. So, we use "spicy hot" as a term and "hot hot" as a term.