Is it safe to take abc plus multivitamins supplements (100 tablets) . and is it right that it shouldn't be taken in hot weather ? thanks in advance

Better choices: It will probably help more than hurt but there are much better multivitamins available. I am not a fan of it because it has synthetic vit e, which is appears harmful, & toxic additives like titanium dioxide & artificial colors. See http://www.Multivitaminguide.Org/ for independent ratings of 101 different brands- any in the top 40 are great! and no reason not to take vitamins in hot weather.