NO A/C!!! Are you aware that its summer out there.
Short term should be fine. Like you said it will be extremely runny but it should help the dissolve ratio while warmed.
Long term heat never mixes well with meds and drugs. It destroys the potentcy and shelf life expotentually determined by the time its exposed to high temps. And cars as we all know can get extremly hot. So ill say it again. NO A/C!!!!
Get yourself a can of freon and try to fix it yourself. If the compressors shot then see a mechanic A.S.A.P. This is an unfortunately tragic scenario thats played out countless times across America and needs to be put to an End. Hopefully when Gary Coleman or Arnold Swartzenneger make office theyll will address this situation with full force and pass a bill to see to it that this never happens again.