Yes! temp makes a huge difference. A 10 beat difference is not even very much under these conditions. When you are hot, the capillaries in your skin dilate this shunts more blood to the skin in an attempt to dump heat. Since you have only so much blood volume, this means less blood left over for the working muscles. Your heart has to work harder to make up for this and does so by beating faster. If it is hot when doing your outdoor training you should use that outdoor AeT. When you train in the cooler weather or indoors you’d be smart to retest.

Scott

Exactly as Scott said, temperatures and humidity make a HUGE difference.

I’m in a situation similar to yours living in Kuwait (high of 112F this week) and most the gyms here have giant glass windows and don’t stay very cool. I see as much of a 8-10 beats per minute difference on my 15% Treadmill hikes in the morning indoors when I use my fan vs. without. It is more prominent the longer I go and stress adds up. I’ve tried jogging outside in 100-110F in the evening but I couldn’t move any faster than a walk without shooting up past AeT, unlike indoors or lower temps.

I think an important thing to consider is the mental aspect, I worry I spoil myself with the fan and cool air. I’m rarely uncomfortable with elements during workouts, Whereas on an expedition you’d probably be tougher. Then again, after the day-to-day heat here, my cold weather on my Rainier climb last year was practically refreshing.

It sounds like you’ve read Roxanne Vogel’s article here on the site? “Cross-Adaptation for High Altitude: Can Heat Training and Cold Exposure Help with Hypoxia?” It’s a great read. Either way, happy training!