At you start on the trail towards the summit of Mount Christoffel, the highest point in Curacao, a sign warns you that you are not allowed to start the hike after 10 in the morning. It's too hot and there is little shade, so start early or risk sunstroke and dehydration.
We started just a few minutes before the 10 am deadline. I remember thinking it couldn't possibly be all that bad. I've experienced 50 degree Celcius temperatures in India, and here the peak temperature would be a mere 33 degrees.
Thirty minutes later I realized I was very wrong. The island is both hot and humid, so the sweat sticks to your skin and refuses to evaporate. The mountain isn't very high (375m), and it only takes an hour to reach the top, but it is a steep hike. They also weren't kidding when they said there would be little shade.
The last 10% or so is very steep and rocky and requires scrambling all the way to the top with hands and feet. By that point the rocks were so hot it was hurt to hold on to them. I spent every minute of the descent wishing we had started at 8am like everyone recommended.
Despite all that, though, it is very beautiful. Curacao gets little rain so the climate is arid. There are huge cacti everywhere. As you walk you hear and sometimes see lizards scatter from the path when you approach. We also spotted two large iguanas fighting over some berries on a tree.
I'd recommend the hike, but strongly recommend starting at 8 in the morning.