Flying Tipplers in Intense Heat

Hello all
I have been flying tipplers for nearly 15 years now. I admit I have never been able to win the top prize but produced some true breeding genotpyes with good flying potential.
My question from the fanciers is that have you ever had a chance to fly tipplers at temperatures ranging between 38-45oC? Some fanciers are able to fly their pigeons up to 15 hours under such conditions. Is it the use steroids or other drugs which help bird to fly for so long or could it be done without drugs/chemicals?

Just to add that I fly my pigeons in Punjab, India and visit my brother (who looks after the pigeons) every year during May-June for the fun. Thanks.