I'm not a morning person and will often ride at night to beat the heat. But I was up early Saturday and planned to join a group for a 50+ mile ride on a familiar route. I bailed after 35 miles and struggled to slog my way home, getting passed along the way by folks who are usually slower than I am.
The weather report didn't look bad, in the 80s before noon, but the humidity was high and it felt much hotter. I've ridden in 100+ degree midday heat and was okay, but those rides were dry. I drink and sweat a lot and couldn't seem to cool off through perspiration Saturday morning.
Reminds me, I need to take a bottle with plain water besides my usual electrolytes, so I can douse myself without getting sticky and smelling like fruit.