I've been running since January, I'm up to 4 miles 4-5 days a week, all outside. I also walk 3 miles outside on my lunch (mid-day) 5 days a week at work. I'm used to being out in the heat/humidity, but at what point is it really too hot to run outside? It's supposed to be in the mid to high 90s for at least the next week and I'm going to get cabin fever if I'm stuck running on the treadmill for that long. Are there any guidelines? Any opinions?