The BT Plus Great Indoors activation will turn the 34th floor of the iconic building into an "oasis above London" where visitors can connect with their family and friends.
There will be five zones that guests can move through, including putting their feet up to watch their favourite sports; an area that recreates a summer picnic in the park; and another that takes people through the sights and smells of the beach.
Guests will be able to attend the activation on 14 and 15 July in one-hour slots. One winner will also be able to stay overnight. The activation is being delivered by PR agency Unity.
Dan Ramsay, consumer marketing director at BT, said: "We launched BT Plus to give customers the very best connection, with our fastest fibre and 4G, whether they’re at home or on the move.
"With the BT Plus Great Indoors, we are celebrating the personal connections that people create in and out of the home, whether streaming a film with your family on a Friday night, or spending time together over a picnic or long walk."