Record-breaking global temperatures could inhibit the ability of aircraft to get off the ground, CNBC reports.

High temperatures make taking off more difficult, especially in combination with high airport altitudes. Hot air is less dense than cold air, meaning jets need more thrust to take off. Engines have to work even harder when the air is thinner, such as at high altitude.

Last summer, American Airlines had to cancel flights out of Phoenix, Arizona when ground temperatures topped 120 degrees Fahrenheit (about 49 degrees Celsius) – higher than the 118 degrees Fahrenheit (48 degrees Celsius) safe operating temperature of the airline’s fleet of Bombardier CRJ regional jets.

Subsequently, the airline and manufacturer determined that the threshold for the CRJs could be safely raised to 123 degrees Fahrenheit (51 degrees Celsius). Embraer also has raised the safe operating temperature standard of its new E190 E2 regional jets.

Larger aircraft, like Boeing and Airbus jets, can operate at temperatures as high as 127 degrees Fahrenheit, or about 52 degrees Celsius.

But that doesn’t mean that travellers can just chill out when temperature records are broken from Los Angeles to Montreal and other cities around the globe. Experts note that hotter weather liked to climate change is also likely to increase turbulence, making for bumpier rides for passengers.