Children and young people in Britain have missed out on more than one million overnight school trips since March, according to a group representing outdoor learning centres and organisations.
UK Outdoors has written a letter asking the Prime Minister, Boris Johnson, to do more to help "save outdoor education".
It warns that companies providing outdoor education for children could soon go out of business.
The UK coronavirus lockdown has had a big impact on many companies, including those running outdoor centres and activities.
Have you had an overnight school trip cancelled? Do you think they should be allowed to go ahead? Let us know by joining in with our vote and commenting below.
If you can't see this vote, click here.
Two million children take part in outdoor education each year, according to UK Outdoors, but lockdown and social distancing rules mean lots of overnight trips have had to be cancelled.
Andy Robinson, chief executive of the Institute of Outdoor Learning, says overnight school trips play a huge part in growing up and giving children confidence "at key moments, for example moving on from primary to secondary".
He is worried that children are losing out on moments "that can spark a lifetime interest in a particular outdoor activity".
Across the UK there are different lockdown rules, but official guidance for all four nations - which is being kept "under review" - still advises against overnight educational trips.
The government has told Newsround that school trips in England can take place, as long as they are non-residential - that means they don't involve staying overnight somewhere. It advises against overnight school visits in the UK and abroad.
The guidance is also being kept "under review" which means they are continuing to look into the situation and they may change their decision in the future.
Since the start of term, schools have been able to run non-residential trips. We keep our guidance on both residential and non-residential trips under review, in line with Public Health England advice.
A spokesperson from the Northern Ireland Assembly told Newsround that "educational visits are currently paused" and that the safety of children and young people is a priority.
This means that school trips involving one or more nights staying over somewhere can't take place.
Other trips can continue though as long as all Public Health Agency guidelines are followed and health and safety risk assessments are completed.
The Welsh government has told us that it is also keeping the issue "under review".
Day school visits are allowed to continue this autumn term, but not school trips which require staying overnight.
The school and the place the school is visiting, should follow rules around health and safety to help prevent the spread of the virus.
Like the UK government's advice, it is also recommending schools don't organise educational trips abroad.
School trips which include an overnight stay away from home are not recommended by the Scottish Parliament.
They said it was not possible to set out an exact date for a review of the guidance, as this would depend on how much the virus is spreading between now and the new year.
It has also said that in the autumn term, if they wish to, schools can continue with non-overnight school trips, as long as all safety measures, including social distancing rules, are followed.
Its guidance highlights that the risk of spreading the virus on a trip which includes an overnight stay "is seen to be greater than the risk associated with a day trip", because "children and adults from different families and households" are "mixing and sharing facilities".
Those who run outdoor centres say they have come up with ways to help keep visitors safe.
Anthony Jones, the Chief Executive of PGL, a UK-wide school travel company which runs activity centres where children stay, said: "Bubbles will not come in contact with other bubbles...We will put in place segregation, one way systems, staggered meal times, separate activities, separated accommodation."
The Outward Bound Trust, an educational charity that uses outdoor experiences to help children to learn, told Newsround more than 17,000 young people, have missed out on outdoor trips since March.
Nick Barrett, from the charity, said: "The need - post lockdown - for the kinds of things that we offer young people has never been greater.
"We can operate residentially in a Covid-secure way, despite having to work with fewer people. We can follow any rules requiring social distancing and we will respect bubbles."
Have you missed a school trip because of coronavirus? Do you think missing out on school trips is affecting your education or do you think you aren't missing much? Should overnight school trips be allowed right now?
Let us know in the comments below.