Salmon Boa (reaching towards heat lamp)

[Trishialad]

Hey everyone!
I am completely new here! (First post!) I own a salmon boa constrictor. I've had him for almost five years now (so he's almost 5.5). Recently I noticed he started stretching up to sit near the heat lamp with his head. I usually keep the water bowl under the heat lamp to allow more moisture to be created in the enclosure.
But I've never seen him sit like this. Would this be an issue to his health, or an indictator that I need more heat for him? Ive been living in the same place for at least a year now. No behavioural changes until now.
Sorry if this isn't appropriate but also thanks in advance!
(Will post pictures of wanted!)