Actually, if you bike daily, your body will acclimate to the heat AND the humidity. It won't keep you from sweating, but you'll be able to cycle despite it without undue discomfort. In industrial environments, this (acclimateization) is why the ANSI heat stress guidelines are absolutely worthless in the South. No work could ever get done if the recommended work/rest regimen was followed. Just start your acclimateization slowly, keep hydrated, and quit if you show signs of heat stress. You don't want to get anywhere near the risk of heat stroke! Also, make sure you (and those whom you cycle with) know the signs of heat stress and heat stroke. Keep a cell phone with you so that if you overdo it, you can phone for help.