I'm starting to think the OP is either a compulsive liar who needs attention or has a death wish or both.
First off, if you are taking PMA and have a temperature of 103, a fucking ice pack isn't going to do shit to protect you - your CORE temperature rapidly rises on PMA. Its not a drug to fuck around with PERIOD, much less with DXM. PMA on its own causes serotonin syndrome. I don't get why someone would even THINK about touching this stuff... And on top of that, I highly doubt that you actually have PMA.
Second, there are some very nice DXM combinations. I found DXM to combine well with tryptamines (as stated by Xorkoth) - particularly well with the non-stimulating ones like the 4-Aco/4-HO series (or just get mushrooms but prepare to puke your brains out). I took 2C-I with DXM before and that was a cardiac nightmare. I can't imagine that 2C-E would be much better.
In general, leave the phenethylamines out of DXM combos (amps, MDXX, 2C*, DO*, etc) as well as piperazines (mCPP, BZP, TFMPP, etc) to avoid nasty stimulation and possible serotonin syndrome effects from certain combos. LSD ... mixes with everything. Not always synergistically but LSD has a very low toxicity profile and mixes with most things. I could see DPT and DXM being an enjoyable experience. I probably wouldn't mix a 5-MeO with DXM because the body load from those is usually pretty bad on their own. Marijuana goes either way. One way or another it will knock you up at LEAST 1 level of intoxication, if not two, but it can take you to a very dark place or a very light and spiritual place. In my experience, the former tends to happen more than the latter.
This last combo - ***DO NOT ATTEMPT WITHOUT AT LEAST TWO TRIP SITTERS PRESENT*** - salvia combines favorably with DXM in midrange doses (we are talking 5 or 10x standardized, NOT anything higher and just one or two puffs at a time). Something about salvia's dysphoric effects and DXM's disassociative effects combine to make salvia a truly amazing time. I can't stress this enough though - make sure you have sober trip sitters present because salvia on its own can get out of hand and on high doses of dextro, you don't have any control of your body anyway.
Just be safe. There's no point in being stupid - especially with DXM. The wrong combo could turn into the worst trip of your life and there is a point where even the trip to the ER won't save you from the miserable death that you will experience if you mix certain substances.