In many places in the US, if you do not have a system to remove humidity from the air in a space, you will fail to regulate your body temperature via sweating, leading to heat stroke and more.
Last summer we had a streak of 45 consecutive days over 100°F where I'm at.
I've never turned on my heater. I don't even know if it works. If it gets cold I grab an extra blanket or wear pajamas. When my AC quit working I moved in with a friend for a few days while it got fixed, because the inside of my trailer house can hit 125 in the summer.
In February I used less than 200kWh of electricity . In July I used nearly 1800.