After 3 weeks of riding in 90+ heat, I decided to drive today because the forecast is calling for 100+ temps and high humidity with a heat index of 105+. Everyone has their limit, and 100 F is it for me. I've ridden a few times in 100+ temps and did not like how it made me feel. Plus the temperatures on large roads are probably at least 5 degrees hotter, and I've got several spots on my afternoon commute with 6-lane roads, full sun and long uphill stretch. I'm starting vacation tomorrow anyway and have a ton of errands to run before I leave and will be riding 300+ miles on my trip.