Why did the frogs that were in the ovens not die?
Da'as Zekenim, Moshav Zekenim, Hadar Zekenim (7:28), Ba'al ha'Turim (on Pasuk 1): It is because they were Moser Nefesh to fulfill the will of Hashem (to enter the hot ovens). 1
Refer to 7:28:151:1. Chananyah, Misha'el and Azaryah, who took their cue from the frogs, emerged alive from the fiery furnace (Pesachim, 53b), whereas Moshe and Aharon, who failed to sanctify Hashem's Name (See Bamidbar 20:12), died and did not enter Eretz Yisrael (Ba'al ha'Turim, citing the Gemara in Pesachim, 53b).