Its hard to confirm what the video crew was experiencing but generally speaking wet-bulb temperatures over 35C (approximate lethal limit for humans) are still very rare on this planet. An interesting study from 2020 dives deep into this subject:
The study identifies thousands of previously rare or unprecedented bouts of extreme heat and humidity in Asia, Africa, Australia, South America and North America, including in the U.S. Gulf Coast region. Along the Persian Gulf, researchers spotted more than a dozen recent brief outbreaks surpassing the theoretical human survivability limit. The outbreaks have so far been confined to localized areas and lasted just hours, but they are increasing in frequency and intensity, say the authors.
They give an example of a 35C heat wave in Iran:
While air conditioning may blunt the effects in the United States and some other wealthy countries, there are limits. Before the new study, one of the previously highest heat/humidity events ever reported was in the Iranian city of Bandar Mahshahr, which almost reached a 35C wet-bulb reading on July 31, 2015. There were no known deaths; residents reported staying inside air-conditioned vehicles and buildings, and showering after brief sojourns outside.
So it seems like wet-bulb temperatures around 35C could be survived if they don't last too long and you stay indoors. The authors also provide a nice map of the highest recorded wet-bulb temperatures per city and it seems like the area around the mangrove swamps isn't particularly record-breaking. Wikipedia likewise has a list of temperature records showing that anything above 35C is very rare (at least for now).
Can humans survive a wet-bulb temperature of 39C over a long period of time? Probably not. Did the film crew actually encounter such a temperature? Almost definitely not.
