BSD
Frum, no it is not Frum. Joseph as usual will give the knee-jerk Chassid Shote response (Noshim are Assur!). Others will care what the Olam thinks, so they can show everyone how Frum (!) they are by leaving Noshim in the cold or rain.
If there is Yichud, it is certainly assur (but then again you wouldn’t take someone out on a date L’toeles there either). See below for my suggestion regarding what to do.
If it somewhere where you would interact with Noshim L’toeles, helping someone out is just as much L’toeles. There is no need to shmooze, and as a geder, you can have your Ema or spouse (if you have one) on the phone the entire trip (my Rov’s suggestion when this question came up).
That being said, everyone should know themselves. If they think that they may be nichshal by helping this person, then lend them your car and you should walk home (or take the bus) in the rain and the cold. As the SA says, “Tzarich Adam L’hisrachech mehaNashim Meod Meod”.