First Aiders said they had been "really busy" all morning, dealing with around 20 cases of fainting.
Margaret Smith and her husband Rod travelled from Victoria, Australia to watch their son Ross compete in the badminton events.
The couple are staying for the duration of the games.
Rod said: "We arrived just as the queues were starting to move but I think it was quite a long wait before then.
"The atmosphere has been very good. We are staying in a flat in the West End and we've had no problems getting about."
Earlier, the crowds at Tollcross International Swimming Centre went wild as Ross Murdoch claimed first place in the 100m breaststroke heat, fresh from his gold medal win on the opening night.
The majority of seats were filled for today's events at Tollcross and the Velodrome.
Police said there had been no reports of any trouble. One officer said: "The security queues have been a bit longer but it seems to be moving now."