If I put supplements (opening the capsules and dumping the powder) into something warm or boiling liquid, would they still be effective?

Depends on the supplements. Minerals are going to survive eating, but many vitamins, enzymes, ... are sensitive to heat.  The longer time of exposure and the higher the temperature the more damage will be done to the heat sensitive compounds.

What about Trehalose, ARA and amino acids?

Anything warm enough to touch isn't hot enough to denature anything. If you can stick your finger into it without scalding yourself (even if it's not comfortable) then it's fine. "Warm liquids" are OK, even for those items that are sensitive to heat. Adding something to a cup of tea or "cool enough to sip" broth isn't the same as adding it to boiling liquid still over the heat.

I'm not familiar enough with the trehalose or amino acids to know if they'd be sensitive to heating, but my guess is that the ARA shouldn't be affected.

Quoted from balletomane

What about Trehalose, ARA and amino acids?

The Trehalose compound is Trehalose and D-Ribose, both sugars and modified citrus pectin.  I'm sure heat won't hurt the sugar, but heat may render the pectin ineffective for the purpose of the supplement.

Trehalose stands up to heat fairly well and can be use in cooking.

larch arabinogalactan (ARA) is stable over a wide range of temperatures.

Amino acid probably depends on which amino acid and the formulations of the supplement. Many proteins (chains of amino acid) are transformed fairly quickly when heated. But most amino acids which make up the protein survive heating for an extended period of time.

Quoted from ABJoe

The Trehalose compound is Trehalose and D-Ribose, both sugars and modified citrus pectin.  I'm sure heat won't hurt the sugar, but heat may render the pectin ineffective for the purpose of the supplement.

Even though pectin is the thing that sets jam & that is heated to boiling point??

Hmmm, interesting discussion! Thanks for all your input thus far. To be more specific, I have been adding Trehalose and sometimes ARA to the oatmeal porridge that I cook for my DH. When I cook it, the water does boil for a few short minutes. Should I add the powder after I turn off the heat then? I find it easier to dissolve if I do it before the boiling point.

Am planning to add some more supplements as he cannot stand taking capsules. The amino acids that I have in mind are:

L-Glutamine  
Acetyl L-Carnitine Arginate + Alpha Lipoic Acid
L-Tyrosine

Would these withstanding heat?

God, I wish my wifey made me these meals.

L-Glutamine is destroyed by heat
L-Tyrosine is more stable but if your are heating it in a mixture with carbohydrates you may want to consider using the N-Acetyl Tyrosine form instead
Acetyl L-Carnitine Arginate  is fairly heat stable
Alpha Lipoic Acid is heat sensitive

I would think adding the trehalose and ARA in oatmeal would be fine (as described above).

Quoted from Christopher1

God, I wish my wifey made me these meals.

Christopher!!!  
I wish you could tell this to my hubby  
But he knows I'm making magical "potions," ! Recently I noticed his gray hair disappearing. His memory is also improving tremendously. Me thinks the Trehalose is working  

Quoted from C_sharp

L-Glutamine is destroyed by heat
L-Tyrosine is more stable but if your are heating it in a mixture with carbohydrates you may want to consider using the N-Acetyl Tyrosine form instead
Acetyl L-Carnitine Arginate  is fairly heat stable
Alpha Lipoic Acid is heat sensitive

I would think adding the trehalose and ARA in oatmeal would be fine (as described above).

Wow, C_Sharp, thanks a lot for this breakdown! Very useful. Now I know what supps to add to the porridge  

Quoted from balletomane

Recently I noticed his gray hair disappearing. His memory is also improving tremendously. Me thinks the Trehalose is working  

He should be very grateful then??!! I noticed the back of my husband's hair is darkening up & his eyebrows are growing in darker I used to regularly pluck out the one or two dark hairs that grew in his eyebrows - as they stood out so much among the white... Really not sure exactly when it started happening, but now I do the opposite

Possum, yes, he is very grateful So, did you give your husband Trehalose as well? Great age-reversal effects, eh!!!   Stop plucking his dark hair so he will notice how he's getting younger  

Actually no I didn't give him Trehalose - I am lucky to even get extra magnesium &/or Vita min B into him
I only pluck the 1-2 light hairs in his eyebrows now, 'cos they stand out among the dark

I see! Yea, it is a challenge for me to get my DH to take any supps too. But the Methyl B he takes with great enthusiasm because it gives him extra energy; and I am happy because it makes him hungry and want to eat my "magic meals," ! Perhaps you could sneak in the Trehalose in some of his favorite food/liquid?