Mishnah Berurah — משנה ברורה

That we do not make a blessing - Even if when he took off the טלית גדול he did not have on his טלית קטן. And this is how the later halachic authorities ruled. And the reason of the "יש אומרים" (literally: "there are those who say" - meaning those with this opposing opinion) is: that since at the time of the removal [of the טלית גדול] he had mind to immediately wear it [again] and that's what he [in fact] did, the removal is not [considered] an interruption. And even if he changed locations between... for example: if he removed it to enter the bathroom or anything similar, this change of location is not an interruption, since he returned and wore the same טלית. And it's not similar to that which the halachic authorities agreed to in Siman 25 [in Se'if 12... and see there in the Mishnah Berurah]... that if one removed his תפילין in order to go to the bathroom, that's considered an interruption. For there it's different, since a bathroom is [a place] that's forbidden to go to with תפילין, it's considered a complete interruption. As opposed to טלית, which by law is not forbidden [to enter into a bathroom while wearing it], except that it's not proper to do so... therefore it's not an interruption by doing so. And know, that if at the time of removing it he did not have in mind to wear it [again] immediately, [but rather] only after some time... even though afterwards he did [in fact] return and wrap in it immediately... [according] to everyone he is required to go back and make the blessing... even if still had on his טלית קטן; For immediately upon removing it, the מצוה has gone. And it's the same law [regarding] the opposite: If at the time of removal he had in mind to wear it [again] immediately, and afterwards he delayed for some time and took his mind off of it... here too, [according] to everyone he is required to go back and make the blessing... even if he still had on his טלית קטן.