The bacteria in Symprove easily survive in ambient temperatures. Once you open a bottle of Symprove, please pop in the fridge to maximise shelf-life. If you are travelling abroad with Symprove, it can go in the hold of an aeroplane without any problems. If your destination is warm/hot and you do not have access to a fridge, we recommend you fill a sink with cold water and keep your Symprove in it to keep cool. Remember to change the water regularly to try and keep it as cool as you can. We have many cabin crew who take Symprove and this was a top tip from them!