The fair opens at Exhibition Park in Canberra on Friday when the mercury is expected to hit 41 degrees. It continues Saturday (forecast temperature 41 degrees) and Sunday (32 degrees).

Lifeline Canberra CEO Carrie Leeson said measures were being taken to keep patrons cool including keeping stalls within the airconditioned pavilions and not having any outdoor stalls.

Icon Water had provided water bottle fillers for the day. Supabarn had donated bottles of water which would be sold for a gold coin donation.

Children's activities on Saturday, Family Day, would also start early at 8.30am and end at 1pm.

Aside from the heat, Lifeline is joining forces with Communities@Work this weekend.

People attending the bookfair can drop off donations of non-perishable food for Communities@Work and its community pantry program, supporting disadvantaged and vulnerable people in Canberra.

Items that can be donated include canned food, breakfast cereals, spreads and jams, pasta, rice, noodles, soups, pasta sauces and personal items such as toothpaste, shampoo and toilet paper.

The bookfair is in the Coorong and Budawang pavilions on Friday (9am to 6pm), Saturday (9am to 5pm) and Sunday (10am to 4pm).

More than 250,000 donated items will be for sale including books, comics, children's books, CDs, magazines, textbooks, DVDs, jigsaws, games and more.

In a new development this year, games and puzzles will be on sale from Friday. Traditionally, they aren't available until Saturday.

Entry is by gold coin donation. Parking is free.

With the bookfair now in its 44th year, we have included a throwback pic or two including a young tracksuited boy from 1998 when temperatures were obviously a little cooler.