Industrial actions in both countries have forced a number of airlines to cancel certain flights
Irish travellers heading to Belgium and Italy today are being advised to check airline websites in advance of departure.
Yesterday, Aer Lingus was was forced to cancel flights EI402/403, EI412/213 and EI450/451 between Dublin and Rome, Verona and Naples due to industrial action.
Travel Journalist Eoghan Corry says delays cannot be ruled out today for flights between Ireland and Belgium.
"In terms of the volume of people going through [Dublin airport] this weekend,. we're building up to the busiest weekend at Dublin airport next weekend, it's about 2 and a half per cent of passengers affected."
So far, the the heatwave across Europe has not affected flights.
But Eoghan Corry says there are certain dos and don'ts for tourists heading to countries dealing with intense heat.
Eoghan advises to "avoid heat during the day, go to the beach and pool early morning anhd indulge the restaurants and other luxuries during the day. That seems to be the pattern of what's developing in the countries that are affected by the heatwave."