Indoor running

Lately, the weather here in Alabama has been in the low-mid 90s in the afternoon and it drops to around 75 at night. There's really no good time to run. Even at the coolest time of day (around 6 AM), the heat index is already 80+ and the humidity is often 80-90%. The temps may drop to the mid-upper 80s in the evening but the humidity begins to rise starting around 5 PM. What can I run in these conditions? I'll be fine in a short interval session and okay in long intervals as well as short tempos. Long runs and long tempos suck real bad! In fact, I find that my pace falls dramatically after about 3 miles. I can handle 5 or so at a decent average pace but no more. That's why I do so much speed work this time of year. How about an 8-10 miler at marathon pace? Forget it. Long runs of 16-20? I won't even attempt it. If I do, it would have to be at least a minute slower than normal with a ton of drinking stops. Preston, I don't know how you can train for Chicago. What's the solution? I do have a treadmill in my apartment but I find it so boring that I can only stand to do 3-4 miles and I just don't think it does as much good as real running. I can use it if I'm looking to do a few miles at easy pace and don't feel like getting in my car and driving to the nearest place to run. So, if I want to do a run of 6-10 miles at a low 7 pace, what options do I have? I can't do it outdoors so it's either the dreadmill or an indoor track at a local gym. I've used indoor tracks before both at Clemson (10 laps/mi) and in Monty (12 laps/mi). The longest distance that I covered was 13 miles (156 laps). Isn't that a little boring? Not really. Once I'm in the zone, I barely even notice the surroundings anyway. The real risk is that all those turns can cause pain in the joints but as long as you don't go in the same direction every day, you're okay. Also, I doubt that I'll use it more than once or twice a week. How do I keep up with all those laps? I could not do it without the Garmin but as long as my pace is even, it's easy. For example, 45 seconds per lap= 7:30 pace on a 10 lap track. If I suddenly see an 8:15 or a 6:45, I know that my count is off by 1 lap.
Here in Birmingham, I tried the Hoover Rec center, which is supposedly 8 laps per mile but I found the air to be awfully stuffy and the distance was clearly off. It was more like 7.5 laps per mile and they made the runners stay on the outside on gave the walkers the inside lanes. WTH? I did not renew my membership when it expired in May. Today, I tried a place called Sport Plex, which is between my office and my apartment. The staff was very courteous and not too pushy but the track was 16 laps per mile (100 meters long) ... supposedly. There were 4 tight turns but at least they were banked and 25 meters worth of straightaway so as soon as you get a stride going, you have to turn again. It's so narrow that if people are walking even 2 abreast, be prepared to stop.
Today's run was a 6 miler (96 laps) and yes, it sure did feel good to run in 68 degree air conditioning. I took off at 6:50 for the first "mile" and never slowed down, finishing in 40:58. That's only 10 seconds slower than PR pace and I was barely winded. Yes, I did feel good but I doubt that it was really THAT good. Maybe it was 100 yards per lap, not 100 meters. I will be looking at other gyms. Another benefit is the chance to meet new people. I met someone in Monty at my old gym who turned out to be one of my biggest fans. She said that whenever I was clearly having one of my bad days, she wanted to stop her workout and give me a hug. Man, that was really touching and I'd love to meet someone like that here.