Can an old (almost 67) runner who has logged over 71,000 miles--most all of it in the South--the last 23 yrs in Tallahassee, FL make a few observations? Thanks. When the DEW point is up over 70, my HR is 10-15 beats higher than the same pace on a 50 degree day. Slowing down comes naturally. Very few folks
PR (Personal best times when it is hot and humid). Hydration is important. If out over 2 hrs some drink enhancers(I use Motor Tabs) are a good idea. You can gradually condition yourself to deal with heat and humidity. Be very careful. Heat can kill.
Biking is much easier in the heat. Sat I rode 60 miles with the temp and humidity over 90. When I run 10 miles in the same conditions I really feel it. May I mention a product that has worked great for me. It is a recovery drink called Endurox R4. I cut the recommended "dosage" in 1/2 and drink a Polar bottle--24 oz cooling down and usually another Polar bottle while showering. It makes a big difference. I recommend fruit flavor and lots of ice.
I lose less salt as a fit athelete than someone who has not trained and acclimated themselves. People run across Death Valley in a 135 mile road race. Enjoy the heat--BUT--be careful. Know the signs of heat exhaustion. Enjoy the journey. Nick