One of the great things about motorcycling is learning exactly how your body responds to different environmental conditions. Even in all of our gear, we're extremely exposed to temperature, humidity, etc. We're probably even more exposed than someone just standing there outside, because we have to contend with intense wind on top of everything else.
Here in the desert wastes of urban Phoenix, we're reaching the hottest part of the year. As if the temperature and unrelenting sun isn't bad enough, we get to contend with rising humidity as well. Those of you acclimated to cooler, wet places might not think the humidity level here is that high, but I can assure you that adding any humidity to desert temperatures makes it absolutely disgusting outside.
Luckily for me, I seem to be well-suited to the heat. Some people, for varying reasons, just wither in high temperatures. I don't look down on those poor souls, by the way. If you can't cope with the heat, then stay the heck out of the heat. Heat exhaustion is no fun, and heat stroke is a miserable way to die - and a common one.
It's therefore a good thing for you to know how your body responds to the heat, and when you should start being concerned.
Sweating, obviously, is a good thing. Your heart rate might also increase a bit as your body tries to cool itself by passing as much blood as possible close to the cooler surface of your skin. Things are still OK if you're a bit flushed and sweaty, though you need to stay attentive to what your body is telling you.
If you start feeling nauseous, fatigued, weak, dizzy, or start getting cramps, a headache or vomiting, you need to take immediate action to cool off. Get out of the heat and into someplace cool. Rehydrate. Get wet and stand in front of a fan. If you're really feeling sick, seek medical attention.
If you stop sweating, have trouble breathing, or have a rapid, weak pulse, you need immediate medical attention for heat stroke. Other common symptoms of heat stroke are strange behavior, hallucinations, confusion, disorientation, agitation, seizure and coma. Of course, if you have any of those last symptoms, you're probably going to have to hope that someone else notices you're not acting quite right and takes immediate action.
Exposure kills people. Even tough people. Don't be a chump - if you start feeling crappy in the heat, take immediate action to cool off. Get off the bike and in to a cool place until you feel right again. Everyone you know will prefer you arrive alive rather than croak trying to show up on time.