Online adverts have been appearing for portable air conditioners claiming to be "designed by former Nasa engineers" and able to "cool a room in 90 seconds". They have emerged on platforms including Facebook and YouTube, but the Advertising Standards Authority (ASA) has now warned the products are often "too good to be true". The ASA told the BBC that some of the adverts it had seen online in recent weeks made exaggerated claims, including that a small device could cool an entire home within minutes or used very little electricity. The BBC has approached Meta and YouTube for comment. Tap the link in BBCNews's bio to hear from someone who tested some of the device. #AirConditioning #AI #BBCNews