My partner is also allergic to mosquito bites and he got a HeatIt and it was life-changing. He previously had to stay home and permanently ice his bites to not get blood poisoning and was in huge pain, but now since it’s always with him on his keychain, he can treat the stings right away before they get too bad and can go out and do pretty much everything now. He still needs to treat the stings regularly, but it’s so much more portable and accessible than the ice packs he used before.
Compared to the larger devices like BiteAway, it performs a bit worse and it’s a bit pricey and the durability is kinda shit, but the fact that it’s always on him and ready to use (as long as you bring your keys and phone), he can treat the bites right away on the go, which makes a huge difference in effectiveness.