Grindelwald for best views and lower altitude but if not taking lifts or trains to higher elevations for a few hours not much to do.

I'm no expert, but it's my understanding that altitude sickness is primarily a problem for those sleeping at altitude (meaning above about 2,400 meters above sea level), but reactions to altitude can occur at lower altitudes and among various people, including (but not limited to) those with certain preconditions. The CDC is my go-to on anything like that, and consulting a travel physician is always a good idea, IMO.
https://wwwnc.cdc.gov/travel/page/tr...high-altitudes

I don't think that is altogether right. Even lower altitudes - 1200m or so - can be a problem to some people especially those with lung-related problems. I lived in Verbier, year round, for over 15 years. My chalet was at 1650m. I had no problem. But now when I go up to Verbier to see my daughter who lives in the village at 1400m I find when I climb the stairs in her chalet I have shortness of breath. And I have no lung problems at all. This is totally normal. You adapt to altitude if you are up high enough long enough. People like me, living "on the plain" and suddenly going to 1400m feel some effects. Heart pounds a bit when walking uphill etc. These are normal effects of altitude and not altitude sickness.

All of the above is totally different from real altitude sickness which you get much higher up. That brings headaches, nausea and dizziness and the ONLY remedy for that is to go down. My son in law who was a guide on Everest says that even 300m lower can make a difference. The real problem is you do not know how it will affect you until you get it.

Personally I think if someone has lung problems or breathing difficulty s/he needs to be careful about how high they go to spend the night. Wengen is relatively low. But when the trains stop running there is no way aside from a helicopter that you can get down from there. You can't just call a taxi and drive down. so I would be cautious in this sort of situation about spending a night in a car free village. Grindelwald of course has road access. That makes a huge difference to one's "peace of mind". And Grindelwald is low - 1034m.

What, exactly, do you question?

Thank you, once more, for your guidance. Bob has some health issues (triple bypass in his early 50s, some COPD now) and is sensitive to motion sickness and vertigo at heights. I think I need to understand more fully what transit into the mountains will entail (the vivid reference above to a cable car filled with people screaming in horror caught my attention), find some youtube videos if possible, and let him decide whether the views, etc., are worth the effort on his part. I'm guessing that will be a no, so we'll need to figure out another middle leg of the trip.

I'm thinking it will need to be Lauterbrunnen or Interlaken (touristy, I know, but ...) Aargh, I thought I had this all figured out but obviously I do not.

Wengen is reach by a train -- no cable car involved. And I thoroughly enjoyed Lauterbrunnen.

Grndelwald is 3392 ft in elevation

Lauterbrunnen is 2,631′

Lauterbrunnen is great but views of high peaks obscured by being in a deep canyon, which is scenic too and does have views of some peaks but Grindelwald has 270 degree or so panorama of mountains, glaciers, etc.

I have no idea about altitudes in feet - but Lauterbrunnen is 800m. 3 feet plus a bit I think in a metre. So 8x3= 2400 feet (foots??) plus a bit. That is LOW for the mountains. In fact it is in a valley...

What I disagreed with in a previous post was the statement that altitude sickness happens primarily to people sleeping at altitude. It happens not just when sleeping but at any time of the day IF you are going to get it. Plus there is a difference between vertigo (fear of heights) and altitude sickness.

Altitude problems usually get worse if you go up to fast like gondolas do.
In this case, forget things like Schilthorn, Aiguille du Midi, Titlis and may be Maennlichen and take the old cog wheel railways that you can leave at intermediate stations if you don't feel well, like
Grindelwald - Kleine Scheidegg,
Wengen - Kleine Scheidegg,
Wilderswil - Schynige Platte,
Brienz - Rothorn
Chamonix - Montenvers
St. Gervais - Nid d'Aigle
Villars - Bretaye,
Zermatt - Gornergrat,
Capolago - Monte Generoso,
Vitznau - Rigi,
Arth-Goldau - Rigi,
Alpnachstad - Pilatus Kulm,
etc. etc.
The best way to not get mountain sickness is just to hike. As human powered locomotion is much slower than any train ride, the body has much more time to adapt himself to the height, and usually it does.

At the risk of being redundant, I would again encourage reliance on expert advice, including taking a look at the CDC information I linked in above.

Error on side of caution. check with your doctor and CDC info as kja says. But again not much to do in Jungfrau Region if can't go above 3-4,000 feet.

I've read the CDC info (thanks for the link), and we'll check with his cardiologist. We used to visit Highlands, NC, which is 4117 feet, and about the same as Wengen. Bob was fine there, so I think the issue is visiting the peaks, not the region in general. I'll look into Wengen for a train-only travel option. Thanks, everyone, for your help.

Wengen is great but I'd stay in a town like Grindelwald, lower elevation with excursions from there to many low-altitude areas. And more like to have medical facilities than isolated Wengen.

Not sure about medical facilities - I think the hospital is in Interlaken anyway... BUT after the last train leaves Wengen in the evening the only way down is by helicopter. IF the weather is OK for one to fly. Grindelwald is on a road - an ambulance can get there in 30mns or less from the hospital in Interlaken. A very long time ago, when I was having a medical problem my Geneva doctor warned me not to go to Zermatt for this very reason.

We'll look at Grindelwald, too, but I fear I may have overstated my husband's medical situation ... his heart situation is stable, he's in OK health, e.g. plays golf, and is more likely to suffer motion sickness and feel yucky for a while after travel than he is to need emergency care. We'll be fine with easy hikes, seeing the waterfalls, enjoying the scenery and whatnot without attempting to reach the top of Schilthorn or Jungfrau.

I really appreciate how detailed and generous y'all have been in sharing information. The forum is an incredible resource thanks to posters such as you.

If he plays golf walking the course and more than 18 holes a week he is in good shape. If he uses a buggy or whatever you call them in your part of the world and drives around the course - I would worry more about his health. Suggest you find a low resort with a way to get to a hospital overnight if needed and start there. Then make day trips up higher...