My BA flight arrival on 7th Jan 2015 coincided with several other international arriving flights. It took well over an hour to clear Immigration - and I am a Canadian citizen, and I was queuing to use the "self service" machines. There were about two thousand people queuing for any type of service. The temperature in the hall must have been about 100 degrees Celsius, with no air circulation. My blood pressure went through the roof from the stress, and I'm sure I was not the only one with health problems made worse by the inhumane conditions. Most of the desks were not staffed, and two were staffed by "officers" (as they like to call themselves) who were actually not accepting people!!! Just noodling away on their keyboards - (Facebook perhaps???) - I am really disgusted and am looking for the right channel or person to complain to - someone who might actually do something - because what I experienced was worse than any 3rd world airport. In the future, it will be Buffalo for me, and I would advise others to think twice about arriving at Pearson - especially if you have health problems that would be exacerbated by queuing for 1.5 hours in an overheated area amongst flu suffers coughing and sneezing.