My 3 month old eats every 2 hours?

my 3 month old has recently gone back to eating every 2 hrs, he use to eat around 3, 3 1/2 hrs (4 oz) about 2 weeks ago. we just came back from texas where the weather was HOT! (100 degrees and above) thats where i noticed the more frequent feedings, my husband is worried. should we worry?