gpfun69

Yes buy him a flight ticket home is good idea if you really want to help him.

https://www.straitstimes.com/singapore/singapore-residents-advised-to-defer-all-non-essential-travel-for-next-30-days-as-part-of
From 11.59pm on Monday (March 16), all travellers - including Singapore citizens, permanent residents, long-term pass holders and short-term visitors - entering Singapore with recent travel history to Asean countries, Japan, Switzerland, or the United Kingdom within the last 14 days will be issued a 14-day stay-home notice (SHN).
For noting, if there are plans to visit Singapore from Thailand.

 

https://www.straitstimes.com/singapore/singapore-residents-advised-to-defer-all-non-essential-travel-for-next-30-days-as-part-of
From 11.59pm on Monday (March 16), all travellers - including Singapore citizens, permanent residents, long-term pass holders and short-term visitors - entering Singapore with recent travel history to Asean countries, Japan, Switzerland, or the United Kingdom within the last 14 days will be issued a 14-day stay-home notice (SHN).
For noting, if there are plans to visit Singapore from Thailand.

 

https://www.straitstimes.com/singapore/singapore-residents-advised-to-defer-all-non-essential-travel-for-next-30-days-as-part-of
From 11.59pm on Monday (March 16), all travellers - including Singapore citizens, permanent residents, long-term pass holders and short-term visitors - entering Singapore with recent travel history to Asean countries, Japan, Switzerland, or the United Kingdom within the last 14 days will be issued a 14-day stay-home notice (SHN).
For noting, if there are plans to visit Singapore from Thailand.

 

You can download from this website as well:
https://www.tatnews.org/wp-content/uploads/2020/03/THAI-Medical-certificate-clarifying-no-risk-of-COVID-19-form.jpg

that illustrates that this whole excercise is not very useful. Obviously, nobody healthy ever measures their body temperature several times throughout the day. When in Singapore recently, many places like temples, tourist attractions, shopping malls, banks, had temp. measurement at the door. Well guess what, my own and my companion's temperature was all over the place, going up and down wildly and rapidly. Two examples:
1. at one of the "trees" at Gardens by the Bay they took the temp. I was rather high (to my surprise) at something like 37.6. We had been walking around in the heat and humidity for some time. They said "sorry Sir you can't enter now". Me: "but there's aircon inside, I'll cool down inside in no time". They: "Sorry Sir can't let you in, please cool down first". OK, no point arguing so went to coffee shop maybe 100m away with aircon. Sat there for maybe 10 minutes, sucked on some ice cubes, then went back. Temperature now about 36.8. All good, can go in now.
2. At a temple, my friend is at 36.7 or thereabout. About half an hour later at the entrance to the bank, 37.5. "Oh you rather hot la" but could go in. Asked about the threshold: 38. Inside he cooled down of course and when going out maybe 20 minutes later went back to the temp checkers at the entrance to re-check, just for the fun of it: well under 37. 
 
The morale of the story: any threshold that has a 37-handle is really useless as that temperature is completely meaningless and not indicative of a fever here in the hot climate.
When I am actually sick I already feel very unwell at a rather low temp of 37.3 and KNOW I have something, even though doctors and nurses then always say "no fever". But this heat-induced 37+ temperature doesn't make me feel uncomfortable or unwell at all. 

Absolutely go (or don't go) wherever you feel comfortable.  It's your holiday and you should be comfortable and relaxed.  
Personally, I have no concerns at all about hanging out in any of the bars (gogo,  Hot Male Beer Bar, Telephone, etc.).  If someone near me was coughing I would probably notice and move a bit away, but beyond that I am simply following the WHO/CDC suggestions about hand washing and I do wear a mask in the stores and BTS, but just because I think it's expected of us now.  
By no means a statistician, but my gut - and a considerable gut is is - tells me that when you work through all the numbers and probabilities, the risk from all the passive smoking at those bars is probably greater than getting COVID-19 now.  So far not a hint of any cases of transmission in the bar scene.  (So far....)
Saunas I'll let others who spend time there address.  

I have an upcoming trip to BKK which was booked 2 months ago. I guess I will probably do ahead, but most likely I would avoid the crowded places like bars and saunas.

https://thanksamillion.sg/thailand-situation-update-on-coronavirus-disease-2019-covid-19-22-february-2020/
 

I have an upcoming trip to BKK which was booked 2 months ago. I guess I will probably do ahead, but most likely I would avoid the crowded places like bars and saunas.