How to safely plug up hole in wall where baseboard heater is

[PeeluckyDuckee]

There's a hole in the wall where the baseboard water heater pipe comes into my condo unit. The problem is there's smell of weed coming into our living room from that hole in the wall. The water pipes are very hot to the touch, I've considered those foam canister that expands to cover the hole but I'm worried because it's flammable stuff. What's the safest proper way to approach this issue myself?

I was thinking about getting some drywall compound and slapping that on there to seal it up. Please advise as I'm very inept when it comes to handy man work like this but would like to try and need some help. Thanks!

 

[skull]

Limits on boilers are set to 180 degrees normally water temp is around 140 when its cold out. Shouldn't be an issue. Foam is only flammable with the gas its dissolved in. Once dry it'll be fine.

I suggest going down to the neighbor and asking to partake might calm you down a lil.