Originally Posted by
cellery
Hi, even though you said northern AZ, as a longtime year round rider in the Phoenix area I'd like to give some tips that still pretty much apply: You will want to be off the road and into shade with water by around 10 AM. Some people would say 12pm but IMO that's much too late and you risk heat related illness going past mid-morning with daily rides. I would plan to be on the road before sunrise before 5am; the ambient temp rises quickly into the mid-90s shortly after sunrise and I have seen 102F by 10am. Additionally, mid-July is when the desert monsoon begins so the humidity level increases to 30-40%. At those temperatures, 40% humidity feels like a sauna and makes dehydration that much easier. Drink a lot of water, like half a gallon every night before bed if you're planning on spending more than 3 hours in the saddle every day. And of course drink at least 24oz water/hr. with plenty of electrolytes (think Nuun, cytomax, etc) to prevent hyponatremia. These are the guidelines I and my friends that ride live by during the summer - I have gone too light on water in mid-July's of the past and have met the ugly face of heat exhaustion a couple times, one time after only 30min in the saddle, nearly passing out - not something to play around with. In summary if you are drinking plenty, keeping electrolytes up and off the road before mid-morning you should be fine.
I would add a couple of things. First the humidity. I understand what you are saying about the humidity increase for those of us from dry places but for someone that is from the Gulf coast like Rwc5830 is, he's going to feel like a dried up lizard most of the time. A slight boost in relative humidity will only shrink the cracks in his skin a little.
The other comment is about water and water carriers. Water in a regular plastic bottle in anything over 80 F is just awful. I agree that you should drink electrolytes but I put mine in the water bottle and let it cook. For plain water, I use a Camelbak. Use a 100oz pack and stuff it with as much ice as you can possible put in it, it will remain cold (32 F) for hours. There are several advantages to this approach. You are more likely to drink water if the water is cold. The cold water also absorbs better. You are also more likely to drink water if it is fairly easy to get to. Having the hose right at your shoulder encourages you to drink.
One of the arguments against Camelbaks is that "they make my back sweaty". Packed with ice, the cold from the melting ice seeps out of the pack and into you back. You back gets a little sweaty but it's also cooled which makes a huge difference to your ride comfort. In low humidity situations, a sweaty back is also less of a problem than it is in high humidity. The evaporative cooling effects of sweat works much better in dry heat than in the wet heat of the Texas coast.