I like hot and humid races. The ones where people are complaining the whole time. The races where everybody comes out sunburned. Or the events where they run out of water during the run.
OK, I don’t really like them, but I think I’m comparatively better in hot and humid conditions than I am in more temperate conditions. Meaning I can get a better placing. Slower time, but better finish spot.
I think this is because I train in a tropical climate, and many of the other athletes in the races I go to fly in from cooler areas. They may not be conditioned to our weather and while they may be faster overall, they crash in the heat.
So training in the conditions you race in may seem really obvious, but not everybody does it (to be fair, it may not be possible).
Another example is hills. Here in Singapore there are not many. So when it comes to hilly courses, we better be ready.
Find out what the temperature, humidity, and course conditions are like in your upcoming races, and try to prepare accordingly.
Pro Lionel Sanders, in Canada, set up his bike trainer in his basement next to his clothes dryer with no fan. He said that easily simulated the conditions he was about to experience in a hotter upcoming race (Florida, I believe).
Others spend time in the sauna or steam rooms to get their bodies used to such sweating.
And those that have the means fly in a month or so early to their race destination to get acclimated. It could be to the heat or the altitude.
Either way, compare your current conditions with your race conditions and see if you can replicate them in any way.