Africa Cup of Nations matches should have four drinks breaks because of "extremely challenging" weather conditions, says one players' union.
The Confederation of African Football (CAF) plans to have two cooling breaks per match, in line with Fifa regulations, but Fifpro wants double that.
Temperatures are forecast to reach up to 40C (104F) in host nation Egypt.
"The health and safety of the players must come first," Fifpro said.
"Any play in temperatures over 34C would mean there is an extremely high risk of thermal injury."
In addition to CAF's existing plans to have drinks breaks in the 30th and 70th minutes, Fifpro proposes players should also rest in the 15th and 60th minutes of matches.
Seven of the group games, including opener Egypt v Zimbabwe , take place in Cairo, Alexandria and Suez - three of the hottest and most humid areas of the country.
Fifpro has also contacted CAF to ask to consider delaying the start of early evening kick-offs "if the heat and humidity make conditions dangerous for players".
The first Fifa-sanctioned cooling break took place at the 2014 World Cup in Brazil, a last-16 match between the Netherlands and Mexico,although plans were first rejected for the 2002 tournament in Japan and South Korea and there were problems with the heat in USA 1994.