Originally Posted by TraumaQueen
I understand why mesh is a bad idea in extreme heat. But if I'm on a long trip with variable weather in July or August, is there a way to make the mesh work?
If you have a windshield, mesh will work for you. Otherwise, as DAKEZ indicated, do something to block the direct airflow at the front of the jacket. Place some sort of wind-blocking layer between the jacket and your shirt. I wouldn't cover the back, as that is a good place for cooling evaporation from low-speed airflow.
My gear is mesh top and bottom, and I ride year round in it.
Last weekend it touched 110 on the way home from a 300+ mile lunch run. Under the jacket I was wearing an REI wool T-shirt, cotton skivvies, and Smartwool socks. That's it for under layers in the Texas heat for me.
Behind the windshield I think that only parts of my arms and legs are in any direct airflow and this seemed to be supported by the fact that at gas stops when I unzipped my jacket the T-shirt was patchy with sweat spots, neither soaked nor dry. I imagine that my core temp remains more constant as the body is adjusting blood flow to the extremities being used as radiators and swamp coolers out in the breeze. But then, I do have a vivid imagination.
After the ride it seemed that I stayed as comfortable as one likely could in this environment, drinking lots of water and unsweetened tea throughout the day. Probably something like a gallon and a half of total fluids consumed, though I was still a little dehydrated.
My gal, riding her own bike and being considerably smaller, seemed to suffer more from heat build-up and fatigue wearing her mesh gear behind a windshield. The mesh was supplemented with one of Frog Togs' triangle thingies that you soak in water and wear around the neck and drape down the body in front or back. That thing would dry to a hard chamois state in less than an hour.
I don't think she consumed more than a half gallon of fluids, and some of that was soda rather than water. When we got home her skin was still hot to the touch after laying exposed to the A/C for ten minutes. Not a good sign. Gonna have to emphasize/encourage drinking more water, Gatorade, etc. on future trips in the heat.
Another difference between she and I is that I mountain bike, and my body is accustomed to shedding heat. She spends most of her time indoors and doesn't follow any athletic pursuits. This may play as big of a part as anything in preparedness for managing temperature extremes.
The body will adjust the internal systems and plumbing to manage the environment it usually spends time in. A sedentary life has little call for high blood flow, sweat production, etc., and those public utilities may not be up to the task of dealing with suddenly imposed extremes.
Physical fitness may be another aspect of temperature management that doesn't get as much attention, yet could be helpful as well.