I read an article that said the only way to train/acclimate to exercising in heat was.....training and exercising in heat. On our cross country ride and RAGBRAI, we have ridden long hours and miles in wilting 95 to 100+ heat. but NOTHING prepared us for riding in heat above 85 degrees with the incredible humidity we found in Minnesota,Wisconsin and New York last summer. Heat is do-able, but heat + humidity is not. Unbelievable! I guess in part that sweating in a humid environment is useless for lowering your body temp? Be careful out there! tokie