You know what? I have been wanting to visit Hyderabad too!
There are direct flights, trains and buses for this journey. Catching a direct flight is the fastest way to do this journey. Direct trains are available as well. Also direct buses are available. You can also travel there by taxi. Bengaluru (Karnataka) to Hyderabad (Andhra Pradesh) distance is 569 km and you can get there by flight in just over 1 hour . Going by train won't be that fast but you will get fares starting from ₹ 286.
The heat there will make you sweat, but it's surely bearable.